MrHonda vs the unruly 1964 250 Scrambler

 The recent acquisition of a sad-looking CL72 lead me down the path of the usual revival techniques, including a new battery, fuel system clean out (tank, carbs and petcock), plus a fresh set of tires and cables.

The carbs were pretty gummy and I tossed the bits into my ultrasonic cleaner for several rounds. There was some residual corrosion and grime in the nooks and crannies, but the bike had been running on them previously, I assumed.

    

CL72 carb specs are #115 main jets, #40 idle jets and a 26.5mm float level. Pretty straightforward, huh? I mounted the carbs on the bike w/o air filters just to get it running and see if the 150/60 psi compression readings would change with a bit of run time. After checking the ignition timing and valve clearances, I hooked up the carbs to a remote fuel bottle and cranked it up. It wanted full choke at first, but settled into a steady idle rhythm with no unusual noises. After about 10 minutes of running, the compression on the low 60 psi side came back up to match the 150 psi on the high side. Things were seemingly looking promising for a quick turnaround for this 62 year-old machine.

I had sealed the fuel tank and rebuilt the petcock, so it was all installed with the seat for a short test ride. Nursing it down the driveway and around the block revealed what seemed to be a big lean flat spot just off idle and an attempt to catch on at higher revs. I limped it home and started troubleshooting.

The aftermarket points and condenser set installed showed running point gaps at .14” and .018” with the backing plate centered on the adjustment slots. Reducing the point gap increases the coil dwell time, but the geometry of the aftermarket points was just off enough not to allow any meaningful adjustments. This was yet another example of the failings of non-OEM point sets on vintage Hondas.

/I had one of the last Pro-Trigger e-ignitions on hand, so decided to install it on this bike to ease the timing woes. Starting the engine up again had no effect on this sudden massive flat spot in the throttle settings. So, onto the carb settings again. I hadn’t removed or checked the main jets in the holders and discovered that the jets were #125! This was puzzling as they were 10 numbers larger than stock. I had accessed a new set of OEM needles which were set at the middle adjustment notch initially. I dug out a set of #115s and installed them, but the flat spot just got worse. It wouldn’t keep running off a nearly full choke condition.

I removed the carbs once again, rechecking all the passages and deciding to change back to the #125s and raised the needles all the way up. Once installed the engine began to show signs of normal life, but not a lot of clean throttle response. I turned back to the ignition system for checks.

In installing the E-ignition system, I removed the spark plug wires from the coil and discovered that the plug wire was not fully engaged into the central spike. The cavity was rusty and corroded so I cleaned out the plug wire hole, but then discovered that someone had connected the coil polarity backwards! I had some spare used coils, so started to check them against the installed ones. I discovered that the secondary resistance readings were 14k ohms on one coil but about 8k ohms on the other five so chose a set of those. I transferred the wire connections to the new set of coils and cut back the ends of the wires to ensure that there was clean wire strands to engage with the central spike. I discovered that the old wire end was not fully pressed into the coil housing, so that was remedied.

It seemed like one cylinder wasn’t firing as well as the other. Checking for spark on a plug grounded to the head, had one side visibly reduced in spark at the gap. I checked the NGK plug caps for resistance problems but they both were reading about 4 ohms. I screwed another fresh cap on the wire and it seemed to get a better spark.

The tank and seat were on and off the bike a half dozen times for test rides that continued to improve, but not achieve a normal function. One problem is that the original fuel tank was replaced with a 1967 tank which does not have a crossover tube function. When fuel runs low on the petcock side, there is still some fuel in the other side of the tank that is inaccessible. One test ride left me feeling that it was running on one side and when I nursed it back home the right side bowl was nearly empty. This brings up another phenomena of Honda twins with duel feed lines coming from the petcock. There are times when the petcock only feeds one carburetor, despite the fact that both lines are the same length and fuel source is sufficient. You can check it sometimes by pulling a fuel line off the petcock and nothing comes out until you plug the petcock fitting with your finger for a moment, then suddenly the fuel begins to flow once again.

There is some kind of fluid dynamics issue going on there, that is not easily understood. If one carb gets filled before the other, then when the line if full, the fuel should transfer to the other port. Perhaps an air lock occurs in the empty line that needs to be bled out to encourage fuel flow once again.

At any rate, the last test ride yielded better running results with the #125 main jets and needles all the way up, however a plug check showed the left side running too rich off the needle setting whereas the right side plug came up clean. I dropped the needle on the left side down to the middle notch and restarted the engine to ensure that it was improving on the left side.

Now that the bike was almost ride-able a new issue of concern arose. Initially, the clutch feel was normal and the bike dropped into gear without the big bang when the plates are stuck together. The bike had been sitting for about six years, so the stuck clutch symptom is not unexpected. However, when I was shifting at low speeds the transmission began to jump in and out of gear while riding, and then it became increasingly difficult to find neutral. Sometimes the light would come on and it was still in gear, all of which leads me to the conclusion that the dreaded engine pull is required to sort out the clutch and transmission woes. This becomes an all day event of removing, disassembling, repairing and reassembling the engine again, then the reinstall into the chassis. These are the reasons why the CL72-77s bikes are not high on my list for repairs and overhauls.

FYI, even if you know what you are doing, a transmission job on a Scrambler is around 6 hours, plus parts. I pulled the engine out, reluctantly, then had to pound away at most all of the screws, then discovered that the clutch cover gasket had been glued on with Honda Bond sealer. The second gear dogs were rounded off and barely had any overlap, which was the cause of the gear jumping. The center ridge on the low gear bushing was rounded down leaving a tiny worn-off ring lodged inside the low gear opening.

I have a number of transmissions from later-model engines, which use the back-cut gear dogs and better gear dog overlap to begin with. The low gear bushing was replaced and almost an hour spent removing the old factory sealant between the cases and then slowly scraping off the clutch cover gasket residues. The clutch plates were replaced with what looks like Barnett clutch discs, but the hub was the original version with 3 retainer wire grooves, but no retainer wires. I re-drilled the hub to secure the first plate and added the vented outer cover. In cleaning the clutch cover I discovered some grooves in the top of the cover where the old primary chain was rubbing up against it, perhaps during the Jumping of the Gears experience. Reluctantly, I installed one of my few remaining new primary chains to ensure that the engine would have a long life. I buttoned up the engine and installed it into the frame. Done for the day. Will finish up in a day or so, then move on to the other projects that are remaining in the shop.

Wrapping up the engine repairs and installation, more problems arose, partly from my lack of care on the assembly of the engine’s bottom end. When the kickstarter cover was installed and the clutch adjuster turned near the index marks, the clutch cable was limp when I pulled in the lever. I started the engine and tried to put it in gear, but it stalled immediately. I first assigned the clutch adjuster misalignment to an extra steel plate installed so the outer clutch plate would just engage with the plate stack. First I double checked the kickstarter cover to see if the steel ball had fallen out. It was still in place, so that left pulling the clutch cover to see what was going on inside.

With the cover off, several things stood out as problem areas. First, the used snap ring that holds the inner clutch hub in place had dislodged, disconnecting the clutch function altogether. I new snap ring was installed and the clutch stack reassembled. When the engine is assembled with the kickstarter cover, you can see how adding or subtracting a plate affects the position of the clutch liver and the clutch adjuster alignment marks. In this case, I removed the extra plate and the marks came closer to alignment, plus the clutch lifter was functioning more normally, arcing through a smooth path when the clutch lever was pulled. As I started to install the oil filter, I noticed that the sprocket was spinning on the crankshaft end! If you are not careful with the conical washer staying in place when tightening down the crankshaft nut, the parts will not stack up correctly and the sprocket fails to spin the oil filter. So, it was a 3 in 1 followup repair, now fully functional again. The third and forth days were devoted to engine removal, repair and re-installation. Final tuning is the last step.

It was still hard to start with the choke, so I opened it fully with the engine still cold and with part throttle, it fired up and caught revs almost normally. I let it warm up then tried the quick around the block test and noticed that the part throttle flat spot was still somewhat present, but once the revs got up around half throttle, it pulled with some authority. I tried a longer half mile downhill/uphill test run and the bike accelerated cleanly with a big handful of throttle, but was still a little lazy off idle. The carb needles are still in #3 slot and the main jets are still #125. After a little cool-down, the plugs came out looking white, giving the indication that the bike was still running somewhat lean, although the sound of the engine seemed to be running perhaps rich at part throttle. At this point, it is trial and error until the end result is a smooth engine take-up from idle towards mid-range and beyond. Ultimately, the final combination was #120 main jets and the needles all the way up. I must have had the tank and seat on and off more than a dozen times, trying to eliminate problem areas and do more diagnostic work to find the causes of poor running episodes.

I spent the better part of 4 days, trying to noodle out the reasons for the sudden engine mis-behaviors and had only gotten about 90% of the issues solved. Make a change, try it out. Make another change, try it out…. It ain’t easy being MrHonda sometimes. I’ve never run across a 250-305 that has defied so many attempts to resolve the running issues. When everything is “correct” as far as compression, ignition timing, carb settings and ignition component conditions, it should run as normal.. sometimes that is not the case.

Bill Silver

aka MrHonda

www.vintagehonda.com

Reunion: Fraternal twins separated at birth. 1969 CB175s

 Well, it is another crazy referral to my already busy schedule of repairs and restorations, but SOMEBODY has to do it. This time, I received a text message saying that a young guy had purchased a set of 1968 CB175 twins, both with low miles, but had been sitting for almost 30 years. The warehouse photos looked promising, but the reality was less than impressive.

                                                    #1 DONE 3/27/26

The fragile side covers exploded when they were pried out of the hardened rubber grommets. I had to use a heat gun on the carb bodies to soften up the old gasoline varnish residue. The forks started leaking as soon as the bike was sitting on the side stand. The air filters were all clogged up and in doing research the air filters and covers had a part change in the 4k range, but this bike is 3130. Exact details are difficult to discover with current part number listings. All the control cables were frozen or seized up. The clutch is of particular concern, as it will require draining the oil and diving into the clutch assembly, then scraping the gaskets and reassembling it all.

The front brake cable, which has the front brake light switch embedded, didn’t move an inch until I disconnected it. The brake cams on the brake panel were seized solid. The throttle cable, was of course, frozen due to the slides which were glued into the carb body bores by old gasoline varnish gum. The original tires were badly cracked all the way around on both sides. The left side of the handlebars was bent up and kinked at the bend. When I put an old fork tube on the end to pull it back down, the tubing split open at the bend site. I wrangled with an eBay seller in RI who had a straight and somewhat clean set of OEM handlebars for $70.

The drive chain was rusty, of course, as were all the turn signal stalks and lens units. Rust was the general theme over the entire motorcycle. Both fenders and the tail light bracket were all pitted. The headlight rim screws were very tough to remove, as the ends were rusted where they extended into the headlight shell.

Once the carbs were removed, I pulled the spark plugs for a compression check. Happily, the readings came out in the 130 psi range, which should be good enough to make it run. The carbs were carefully dismantled and bathed in the ultrasonic cleaner for about a half hour. New kits are coming in with the other $400 parts order from 4into1.com I did find a new pair of $100 air filters from DavidSilverSpares.com, here in the US, fortunately.

I spent a half hour removing the front brake panel from the cable and the front wheel, then dismantled it to clean the brake cams and scuff up the asbestos brake shoes, just a bit. I was pleased to see that the inside of the brake drum was still shiny and clean.

The petcock, which was to be replaced with an OEM part, was almost rebuildable, apart from a slotted screw in the retainer face plate instead of a normal cross head screw. The owner had attempted to clean the inside of the fuel tank. We’ll see how well that works out once it is up and running again.

The tubes and rim bands came in ahead of the tires, which were coming from two different locations. Fortunately, the little tires on small bore bikes are generally easy to change with hand tools. The rear tire came in first, so as I extracted the rear wheel assembly, I noticed that the tire was a “Swallow” brand Korean unit in 3.25x18 vs the stock 3.00x18 size. As the wheel was inspected, there were big gouges in the inside of the left chain adjuster, consistent with a thrown drive chain at some point. The bike only had 3800 miles showing and the front tire was definitely the original Yokohama rib showing big cracks in the sidewalls.

The rear wheel sprocket was removed for surface cleaning and the new tire spooned onto the rim. A new drive chain was installed and the whole back end was tidied up as much as possible.

While awaiting the front tire’s arrival, I removed the wheel to clean up the brake cams so the brake action would be restored with a new cable. This left me in a dilemma as the OEM front brake cable has a built-in front brake light switch and these cables are difficult to find and quite expensive. A couple did turn up on eBay, one at $49 and another at $29, but $44 delivered.

The fork seals arrived and with the front wheel in a temporary installed state, I removed it and went about taking the fork legs off. The left side came out easily, but there were ominous signs of rust down inside the chrome sleeve that sits atop the fork slider. Normally these are tapped off with a screw driver around the bottom edge of the sleeve, but this one would have none of that attempt. After spending a half hour trying to tease it off the fork leg, it was apparent that the sleeve was rusted into the fork housing and needed to be replaced. Back to eBay for a set of good-looking forks from a seller in the mid-West for $107 delivered.

The replacement forks arrived, looking very clean, especially at the chrome sleeve junctions. Getting them off without damage will allow for a fork seal replacement and then refilling and installation. Also, the replacement handlebars had a few rust spots, but were miles nicer than what was on the bike as it arrived. All the handlebar switches will be swapped out and then the fresh bars installed with a new set of cables. I was able to track down another of the rare front brake cables with the brake light switch installed for $44, so we’ll keep that function going for these new riders.

I removed all of the headlight wiring connections in order to facilitate the replacement of the bent up handlebars. In the meantime, I laid the bike over on the left side and removed the clutch cover. All the screws had never been disturbed since assembly in 1969, so the use of a 3lb sledge hammer was employed to coax the screws loose. Amazingly, the clutch cover popped off with the gasket completely intact, a rarity in my experience. The clutch plates were a little sticky but didn’t show signs of the kind of “stuck-clutch” feel of the clutch lever when it arrived. A new clutch cable will be installed with the handlebar swap and hopefully the function will return to normal. Happily the inside of the engine looked very clean, owing to its low miles condition.

The new tire arrived along with the cable and handlebars, so a few more hours of work lay ahead.

Winding it down…. 2 weeks later. 

So, the handlebar swap took a good bit of time. I had to saw the bent part off in order to retrieve the switch harnesses. The outer sleeves were all crispy and unwilling to move through the inside of the bars easily. Once the switches were installed, then the bars went onto the bike and all the wiring connectors repaired and connected. The cables had to be installed and routed, then adjusted correctly. The last thing was to drain the very dark oil and check the valve clearances and ignition timing. 

Of course, spark advancer was rusted to the end of the camshaft and it took flooding the advancer with penetrating oil and my heat gun to get it loosened up for cleaning and adjustment. The points had worn down causing the ignition timing to be quite retarded. The drain plugs on these engines uses a 19mm socket for removal. I had to use a 2ft long extension bar to finally break it loose. Ugly oil splashed out into the drain pan. Like every other screw on this bike, it took an impact driver to loosen each and every one of them. Once the dyno cover was removed, the timing could be set and it was looking like it was about to come alive once again, since 1997!

With the carbs done and installed and new oil and timing checks, it was time to hit the starter button!

Thankfully, it burbled to life quickly and sounded pretty good, apart from the extra exhaust noise coming from the muffler holes. I cleaned up the mirrors and installed them for the first test ride since the last century. Happily, it was feeling like I remembered mine back in 1969, in Puerto Rico! I rode it for about 5 minutes, including a good pull up my test hill and it ran perfectly. It’s still on the ugly side due to all the rust on the chrome and alloy bits, but it seems safe to ride and enjoy once again.

Here, in the end of March, I am juggling repairs on the 1961 CB77, a 1964 CL72 and this first of two CB175s. So, depending upon the parts available, the work load was distributed between the three bikes.

The CL72 finished up first, so will be first out of the shop, followed by the Super Hawk. Once this CB175 is up and running, its stablemate twin will swap out for this current project, no doubt with similar ills. So, no doubt the next CB175K3 will get its own story. Then the fraternal twins will be reunited, both in running condition and ready for the road.

Bill Silver

aka MrHonda

www.vintagehonda.com

MrHonda does a 1961 CB77 2.0 part 3

 

The NOS wiring harnesses were laid over the frame and little aluminum wire bands installed. With the rear fender in place, the modified tail light was bolted on, then the wiring problems began. The tail light wires feed into a channel on the left side of the bike, where they meet the wiring harness next to the rectifier and fuse holder. Feeding the blue and white tail light wires into this channel always seem to be a problem. In this case I had to insert a piece of thick steel wire to clear out any blockages in the channel, then attached a smaller thin wire to one end and pull the wires back through the fender channel successfully. Trying to feed the wires in, one at a time, were not successful. Of course, all the attachment points for the tail light base, the tail light bracket, the rear fender and then to the frame all had to be ground away so there would be a sufficient ground path for the tail light functions.

Up at the headlight shell, the wire connections were made but the starter button wire was a thin, 22 gauge wire that had been spliced in with some tape over the little plate that holes the contact button. I pirated a new wire from a Benly starter button housing and filed it down to fit. Reusing the dimmer switch which was on the bike required some extra wire repairs.

The NOS, newly powdercoated front fender installation was a chore as the mounting bracket hole on the right side was off about a millimeter. Then, the fender braces had to be wrestled into place. One end of one brace needed to be filed down to clear the end of the fork slider.

With wheels, an engine installed and fenders attached, it began to look like a real motorcycle once again. The bike was picked up on November 19, 2025. So, three months later, it is getting closer to completion.

More challenges arose as the incorrect speedo, having been just freshly rebuilt wouldn’t fit into the correct 1961 CB headlight shell. Part of the front end replacement included a later headlight shell which isn’t a match for the speedo with a high beam indicator. I really didn’t pay attention to how it was installed previously, but it wasn’t a match anymore. I contacted my good friends at Foreign Speedo to request putting the other 1962-63-ish speeedometer into the hurry-up queue. They responded with a finished product in about a week and it was a beauty with an HM logo on the face and a stainless steel bezel. A correct speedo packing came in from Thailand, so it was finally taking shape again with the correct headlight shell nestled into the fork bridge.

    Incorrect speedometer fitted into a later model headlight shell. Now replaced with correct parts.

For some reason, a correct clutch and throttle cable seemed to be in short supply for the early handlebars, so I ordered a set from www.cmsnl.com. They normally are able to deliver parts from Holland in a few days, but I got a note from FedEx stating that the parcel was held up for inspection of contents, probably meaning tariff charges. The package was delayed a few more days, then finally arrived looking like it had never been inspected unless they repackaged it at FedEx. A few days later a letter came from FedEx, which I feared was the dreaded tariff charges. Instead it stated that the fees were $.75 and it was not a bill. ?????

Moving along, the installation of the left side one-piece muffler was shockingly a mismatch for this engine and frame for some reason. The muffler was one of a set that was purchased from a seller back East for $300. Then there was $150 in shipping fees, but when they arrived, the chrome surfaces were all pitted. The mufflers went down to Mexico for replating, as they were new items and wouldn’t contaminate the chrome vats with old oil and gas deposits. Plating was $200 each, so now the “value” of the muffler systems was nearly $1,000. When the one-piece mufflers are created, the joint between the muffler body and the header pipe usually allows for some rotation of the muffler, but not any fore-aft motion. The left side bolt hole into the engine cases was about an 1/8” off and the rear mounting points were also incorrect. I had to slot the mounting bracket holes to get a bolt into the inside mount, but it still didn’t match up to the footpeg bracket hole.

I tried to double gasket the header into the head to see if that would pull the muffler forward, but it didn’t do much to alleviate the problem. More bracket mods finally got the rear inside bolt to fit into the bracket, but it was somewhat in a state of tension.

Once the clutch cable arrived, I could fit up the kickstarter cover, which had a machined bushing installed to remedy a loose kickstarter gear shaft fit. That was another $150 repair. With the kickstarter cover in place, the clutch adjustments were made and that allowed for the installation of the right side footpeg, the new rear brake cable and new brake light switch to be mounted in place. I prepared my self for another tussle with the right side muffler and was prepared to be disappointed.

To my great surprise, the right side muffler pretty much matched up to where the mounting points were on the bike. HOWEVER, I had overlooked the fact that the hole in the engine case where the long 8mm bolt holds the muffler to the engine was bored out to about 10mm. The hole was too big to fit an 8mm Heli-coil in and make it fit. Finally, I drilled the hole out to 12mm, found a 12mm bolt then cut the head off in order to make it fit flush into the engine case. I drilled a hole all the way through the bolt’s length to fit a 8mm bolt, but in the end the SAE drill bit was a little too big for the 8mm tap to catch threads fully. As a last resort, I drilled out the 8mm hole with the 8mm Heli-coil kit and was able to finally anchor an 8mm bolt into the engine case.

I discovered that I only had one exhaust baffle for the set of mufflers. Apparently I sold a set along with some CB used mufflers and only had one NOS one left. I put out a plea to the forums and a kind man offered to ship a good used baffle to me for free! So, finally we are getting towards the end of the long project, but then an electrical mystery arose. The tail light bulb comes on when the ignition switch is in PARK, but not when the running lights are ON. Everything else works except for that! The white wire goes from the tail light directly to the terminal on the ignition switch.

So, now it is left with installing an ignition system and firing it up! The carbs were cleaned and rejetted. A new correct thottle cable was secured and installed. The drive chain was installed and I can finally see light at the end of a long and dark tunnel. 

Bill Silver

aka MrHonda

www.vintagehonda.com

MrHonda does a 1961 CB77 2.0 Part 2

 BACK TO TO THE ENGINE

With the cases de-greased, I was able to begin a re-assembly of the bottom end. I opted to just use some Cast Coat Aluminum spray paint to use on the bottom cases, cylinder head and the top cover. Getting them all vapor blasted would have added another $400 to the ever-growing price tag. I rifled through all of the NOS transmission parts and managed to put together an upgraded transmission with all back-cut gears. The crankshaft was carefully reinstalled on the locating pins, being careful not to dislodge the main bearing pin for the rotor end of the crankshaft.

Even after soaking in a hot tank the leftover gaskets were stubbornly still adhered to the engine cases, requiring an additional 45 minutes of careful scraping and leveling off of the mating surfaces. When you come across the old asbestos-based gaskets, you will find them to be quite challenging to dislodge.

I used some Moto-Seal, which is equivalent to Honda Bond and tightened all the fasteners equally. The engine came with the bottom center front studs having plain washers and nuts vs. the cap nuts and copper sealing washers. There is a special long 6mm nut that goes together with the aluminum sealing washer for the bottom case, just below the oil outlet, however they were installed on the opposite side of the cases. There were a lot of little assembly errors discovered as I went along.

Once the cases were married together, the engine can be flipped over to add a new camchain guide roller. BTW I installed an endless camchain, this time, over the crankshaft before assembly. I fed it over the new guide roller and it awaited being pulled up through the cylinders and onto the updated camsprocket.

From 1960-62, Honda did NOT use a primary chain tensioner system for all of their 250-305 engines. I had to sift through my stash of parts to find a good shift shaft, which has to be installed before the primary chain and sprockets are fitted up. I was using a later rubber-cush drive clutch outer, but when I pushed it fully onto the main shaft, it started to bind up the shaft and clutch hub. I had to swap it out for another good used part as there was some kind of machining flaw with the other one.

I ditched the big 6 plate clutch pack, which has no retainer wire grooved fitted to the clutch hub. I have been upgrading the clutches to the later 1966-67 CB/CL77 clutch assemblies with a two groove inner hub to hold the 3mm Plate A and then a set of friction and steel plates in the next groove. I used some similar sized fiber plates, which are probably from a CB350 with lots of radial grooves and are only slightly thinner than the 268-020 OEM plates. The outer pressure plate has four angled holes to help evacuate the oil trapped inside the clutch assembly, which eases the tendency to slip.

I had a NOS clutch cover and oil pump cover for the left side, so replaced the old originals that were scuffed up and worn. All new oil seals were installed in the engine along with a NOS neutral switch. The oil filter received a good cleaning and new o-ring. It had about a 1/16th inch of crud built up inside the filter rotor. The clutch cover has the early small hole design, so you must remove the whole clutch cover to clean the filter rotor.

TOP END TIME

I thought I was all set with the newly-discovered .75 piston rings, but as I was installing them back on the cleaned pistons, I discovered that the top ring was actually a STD ring, instead of .75. I recalled seeing some various pistons in a spares box and luckily there were two .75 pistons with new rings installed. I transferred the top ring of one onto the 1961 pistons and then replaced the piston pins with NOS items that came from the NOS parts stash. I had difficulty getting the cylinders down over the piston rings on the right side and although I has scraped the carbon out of the ring lands on the piston, there was a little tight spot that kept the ring from seating deep into the ring land groove. A little filing of the groove finally allowed the ring to compress properly and the cylinders dropped down easily. I had the cylinders honed before installation and there were a few scratches on the right side where the broken piston ring was rubbing up against the cylinder wall, but it should be okay to run that way, I hope.

I think the machine shop did a bit of bead blasting of the combustion chambers on the head as it was all shiny and clean. I came up with a good used later model camsprocket and matching camshafts to replace the 3 lb original camsprocket. The rocker arms still looked good, so they were reused with the pins and the valve springs and all the valves, after they were cleaned on the wire wheel.

The completed head was gently slipped back over the studs and the camchain pulled up to meet the camsprocket. In order to assemble the engine with an endless chain, you must install the inner cam bearings in the head, then slip the camchain over the tapered side of the sprocket in order to finally lift it over the sprocket teeth. With the right side piston at TDC, the camsprocket flat with the punch mark must be leveled with the cylinder head surface and then the cams are inserted from both sides, as you match up the master spline sections together. The cylinder head must be secured with a couple of short 3/8 drive sockets and nuts on top to compress the head and base gaskets enough to allow the camshafts to be inserted into the camsprocket. Care must be taken to index the point cam mark at the top as the right side cam is driven into the sprocket splines.

It’s a tricky business, doing the endless chain, but reduces the chances of a master link failing. It is hard to find new camchains that come with a clip-type master link now. I have found that OEM Honda master links will fit into some of the aftermarket camchains once the chain is separated. Honda’s 250-305 engine share the same camchain length as the 350 twins and SOHC 750s, which all run endless chains.

Chassis powdercoat

Once I finished disassembly of the chassis, it was time to haul it all out to the local powdercoating shop to make it all black again, except for the fenders and side covers. I had to have a little piece of the chain guard bracket re-welded and the fork crown holes were welded up and the local polishing shop finished the welds off so it looks like a 1961 crown, instead of a 1962 version.

All of the nuts and bolts came off and went into a big bin for cleaning and reassembly. What I failed to notice was that the shocks were held onto the swing arm with 8mm bolts instead of the normal 10mm types. After the shock covers came back and the re-chromed lower covers were all installed, I noticed that I didn’t have the correct lower shock bolts. I ordered some grimy used ones from an eBay seller, but in the meantime I discovered a pair in a separate box of parts. After I cleaned them up on the bench grinder wire wheel, I discovered that they didn’t fit the shocks! I had noticed that the original shocks, which have alloy covers were steel instead, but it finally dawned on me that these shocks were from a CB160!

The problem with most powdercoating shops is that they are not fully tuned into which parts need to be covered up and which are not. I spent a couple of hours removing powdercoat from the inside of pivot holes, the steering stem lock housing and worst of all the rear shock bushings on the swing arm were burnt out and all that was left was the outer sleeve, still stuck in place and powdercoated around the edges.

I attempted to cut out the sleeve with a hack saw blade in two places, 180 degrees apart, but that didn’t work. Finally, I dug out a box of seal and bearing drivers and in the bottom was a small chromed steel slug with a hole in the center. The OD matched the OD of the bushing sleeve.

BYW, the little bushing tool had RH initials inscribed on the edge. This was part of the tools and equipment that I received from Bob Hansen, the “father” of the CB750 prior to his passing a number of years ago. I didn’t remember even having it, but I think the lower swing arm bushing for the CB750 rear shocks is the same as the CB77 part. So, thanks Bob, for helping me out in a difficult situation.

Not having a hydraulic press left me with few options. Finally, I used a tapered drill bit and knocked a small edge into the bushing shell. Using a deep socket to allow the bushing sleeve to move into, the little steel slug was positioned into the tapered hole and the swing arm held together all with both hands in my bench vise and I managed to square up the tool and tightened it all up. The vise handle is only a foot long so didn’t have enough leverage to apply serious pressure to the little tool piece. Once it was secured in the vise, I grabbed my trusty, spare CB77 fork tube to apply some more force to the vise and it slowly pushed the tool through the swing arm hole and out came the bushing sleeve! I applied the same strategy to the opposite side bushing sleeve and finally the holes were cleared out so new bushings could be installed. I was able to use the vise to push the new bushings in place. You have to install them flush with the swing arm surface or the shock clevis won’t fit down on the shock mount.

There were more difficulties with the steering damper parts. The bottom of the steering stem was not covered before coating, so more filing and grinding was required in order to fit the damper parts on the bottom of the stem. Honda used several different parts for the steering damper, including the bottom spring and the spring holder that the damper shaft is threaded into.

I have to turn the frame upside down in order to install the swing arm and the centerstand parts. Somehow I wound up with two of the longer centerstand bolts, instead of one short and one long on the side where the side stand bracket attaches to the frame. Sifting through various boxes of parts failed to unearth the short bolt, so I had to order one up from an eBay seller in TX. The bike was missing the centerstand when purchased, so I had to rob one off of the rolling chassis that I picked up in N. Cal.

There should have been a correct set of bolts on that bike, but the short one went MIA, so things have slowed down until a new one arrives. Installing the centerstand is tricky on these bikes, as the spring seems to be way too short when using a spring installation tool. I had found in the past that I could attach the short bolt loosely in the right side and hook the spring to the left side anchors, then use the centerstand as a lever to stretch the spring out enough to allow the long bolt to go all the way through the frame and bracket holes.

I did install a tapered steering head bearing kit for the stem to do away with the 37 little #8 balls from escaping in the original steering races. The upper stem bolts and hardware were NOS pieces from the Colorado parts stash. Those parts, in addition to the box of CB77 spare bits that I have acquired over the years are finally being put into play for this oddball project.

The wheels and brakes were all disassembled and cleaned. I actually swapped out the wheel assemblies from my parts bike stash from N. Cal, as the original rims were very rusty. I discovered a set of re-chromed spokes that had been stored away, so cleaned up the rims, de-rusted the brake drums, wire wheeled the brake linkages and reassembled the brake panels. I wound up using the ancient, but unused Michelin tires that were parts of the N. Cal stash, despite the shipping tag that showed a 1997 purchase date! The beads were so strong that I had to have a motorcycle shop install them. The bike is being revived not fully restored, so I am cutting costs where I can, just to get it running once again.

The assembly went slowly, as the needed small parts drifted in from eBay sellers, CMSNL and other sources. Once the centerstand, sidestand and swing arm parts were attached, the frame was spun over and supported by a long pair of tie-downs that were hung from an overhead rafter. I slid the rear wheel into the swing arm, temporarily, to help balance out the weight of the front forks and wheel. As that progressed, I had to figure out how to mend the missing battery box piece, which attaches to the front of the rear fender. A trip to Home Depot yielded a piece of sheet metal which I cut down to the size of the battery box and then flared one end to accept the fender bolts.

The holidays interrupted the powdercoating process, so the silver parts were delayed a few days. When they were finished, I was able to attempt the rear fender installation after removing the rear wheel again to access the forward fender bolt holes. I slid the metal repair patch back towards the fender and marked the holes. I drilled the new holes in the patch piece, bolted up the fender to the edge of the sheet metal and then used GOOP to glue the patch piece down to the remaining part of the battery box. Not pretty but you won’t see it, unless you remove the battery.

I rolled the chassis back off the bike rack and wheeled the engine over to install in the frame. Juggling a 115 lb engine on a small floor jack is always a challenge, but I was able to maneuver the jack enough to start the engine upwards into the frame mounts. Once the holes start to line up, a few big Phillips screwdrivers poked into the bolt holes help keep the installation process going until all the mounting bolts are finally installed. Once the engine was put in place, the rolling chassis was rolled back onto the bike rack for more part installations.

TBC

Bill Silver

aka MrHonda 

www.vintagehonda.com

A Wild Week of Mecum and other surprises…

 It’s a 350-mile one-way trek for me to drive up to the South Point resort hotel for the annual Mecum Motorcycle auctions, featuring 2,000 motorcycles for sale. Prices ranged from $500 to $330k with Mecum taking in money from both the bidder and the seller, per usual. Not mentioned clearly is if the bikes have a title or not in most cases. If no title, the bikes are NV taxed at 9% of the sale price! I got hit with an extra $400 last year on my CB77 racer, so it is a heavy hit for most unsuspecting buyers.

That aside, it was another amazing year of bikes of all shapes, sizes, makes, models and years. Board track racers were selling for $100k, Honda Z50s for $10k and the pair of un-crated CB125S bikes sold for $25k! There is no rhyme or reason to what some bikes sold for. Harley Baggers were selling for $2500 in some cases. When I walked into the room on Wednesday morning an SL125 and SL175 both were hammered for $10k. The prototype CB750 belonging to “Mr. Sandcast” Vic World hammered out at $313k and the George Beale RC174 incredible replica went into the $330K range.

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                                            Mislabled 1961 CB77 #58, sold for $10k

I almost passed on making the long journey again, as I had no plans of buying anything and staying at the hotel was $90+ per night last year, even with the discount. The one big draw is meeting up with many of my friends and acquaintances, many of which go back well into the last Century. I sold some CB750 parts to Vic World back in the 1980s, when he was on the search worldwide to build his collection of parts to build up sandcast CB750 bikes. My friend Tony Moseley, who is a retired Kawasaki manager was last seen at Daytona back in the 1990s, as best as we could recall.

Part of the encouragement to drive up, was from a message from my friend Don Scott Peterson, who lives in N. Las Vegas. He’s been wrangling old Hondas for many years, rebuilding and restoring some rare machines, including the #2 CL77 some years back. Mr. Peterson contacted me a few months ago about encouraging me to come up and help him clear out his leftover Honda parts, as he was down to two final machines: a CL77 and a CA77. He offered to allow me to stay at his place for free, but the downside was that he was 25 miles away from the auction site, which turned into a 30 minute drive each way during the week. A round trip in my Tacoma worked out to about $6 in gas per trip. Costco was selling regular for $2.89 when I was there. I trekked back and forth during the Wed-Friday events, having dinner with a couple of groups at the end of the day.

Scott started to roll out his “leftovers” and I got the feeling that it was going to fill up my Tacoma’s bed and then some, so I ended up renting a U-Haul trailer for $140 for the one-way drive. The parts ranged from C200-early CT90 models, to various engine parts for CB/CL72-77s. The sparkling shiny alloy CL72 racing gas tank turned out to be a copy made in India, which was quite a feat of design and assembly, but there were a lot of details that were less than factory-correct. Still, they are impressive works of art, assuming that they will hold gasoline correctly. I worked with a customer who had a metal CL72 tank from India and the petcock holes were incorrectly drilled. It had to be re-welded twice to get it functional.

Other boxes of parts revealed a bin full of CB160 transmission parts, gaskets, wiring harnesses and other model-specific items. A number of 250-305 cylinder heads, bare and complete weighed down the truck bed right away. A lovely C72 fuel tank and headlight shell were already painted and ready to use. Other interesting bits included a set of big bore pistons (+3.00mm), along with a set of unbored cylinders and a crankshaft.

Exhaust parts included some rough Dream mufflers, a WEBCO straight pipe for an S90, and some CL72 exhaust pipes that were corroded around the head pipe bends.

Having already renting a 5x10’ storage space locally for the N. Cal-Los Gatos CB77 parts haul, it was clear that more space would be required. A call to the office mentioned ONE last 5x10’ space left and I could go on a waiting list for a 10x10’ street level unit. I asked them to hold that one and headed for home on Saturday afternoon.

I hauled the trailer and truckload of parts back to San Diego in about 6 hours, parking the rig in front of the house overnight. I joined my Sunday riding buddies for our morning breakfast ride and then came home, grabbed the truck and trailer, then headed for the storage company. The available 5x10’ was sufficient for loading up the parts. Thereafter, I returned the trailer to the local U-Haul store and was done for the day.

I’ll be adding various parts from the new supply to various forums in the weeks to come. I’m working on completion of the 1961 CB77 #557, so I can clear if off of my work bench. Because of my friend Tuan, who steered my onto the CB77 in Burbank, now I am committed to driving back to Riverside to pick up a 1964 CL72 which he bought and then re-sold to me, as I am much closer than Wisconsin.

So, it’s been a busy week in Lake Wobegon… sorry La Presa, CA. The beat goes on and the stories will continue.

Bill Silver aka MrHonda

www.vintagehonda.com

MrHonda does a 1961 CB77 2.0 PART-1

I don’t monitor the Craigslist ads in the LA area, so wouldn’t have known about this until I got a quick note from Tuan Tran, who lives in WI and is a very avid collector of vintage Honda bikes and parts. The post was kind of crazy but the photos indicated that the bike, which had some definite customization way back in the 1970s, was indeed a 1961 CB77 Super Hawk. Here’s his CL post:

This 305 CB77 Honda Super hawk lived in a garage since 1976, then my neighbor sold it to me and I got it running! Everything is filmed on video:

https://www.youtube.com/shorts/-cUGKFQ8cj4

Everything is there and it starts every time,! Clutch is soggy and everything needs attention for safe riding.
Electric start works perfect. Starts right up. Your wife hates it already. Have original Pink Slip and key
video of it driving for first time in 46 years here:
https://www.youtube.com/watch?v=XDNBNc9KgZw

You can always tell the frames by the smashed flat rear frame section where the seat bolts slide in. Honda added some formed tubing later on and this caused the seat pan bolt pattern to extend about 1” further out. There are dozens of 1961-unique features that were changed and superseded to a more improved design from 1962 onward.

The seller told a crazy story about finding the bike chained to a telephone pole just blocks from where he lived in N. Hollywood. He was first to call the owner and get a shot at buying it at the final price of $400. It did come with a CA “pink slip” title, but the VIN numbers used were the engine numbers of CB77-110563, instead of the correct frame number CB77-10557. CA didn’t even use the engine numbers as the additional part of the titles for a few years after this one, issued in 1977.

The seller, Paul, sent a ton of videos and photos to my phone which answered a lot of questions. Paul realized that my name and city = the infamous MrHonda, so he was excited to share all the details and answered numerous questions about the bike and the story behind his discovery.

The down sides are that the tail light is a later 1963-66 series, the speedometer is a 1964-65 unit. The handlebars are probably CL72, along with the cables. The front fender is one of the “Superior” aftermarket replacements from Dixie International, which does fit the Type 1 forks, but is chromed and squared off differently than the OEM fender. The correct transmission cover, which has a big relief at the back to wrap around the rear breather tower was missing and a new one on eBay was $150. Looking at the fork bridge, it appears to be one from a 1962 model which has the little packing holes drilled down into the sides of the oval speedometer holder portion. Certainly, on the plus side, the engine runs, the rear shocks seem to be in good condition. The overall condition is in the “good” side,but needs a full restoration or at least to undo the custom work and make it ride-able again.

I have wondered about my sanity at times, especially when I drove over 2,000 miles to retrieve old Honda parts recently and know that it will take many months to possibly recover all the out of pocket expenses in the process. But, in considering how I might restore the “custom” CB77 back towards original condition, I know that I have a lot of NOS generic Honda parts that will fit this bike, that are not 1961 model specific. So, somehow it all works out in the end, I guess. I started this story on 11/15/25, just on the basis of the conversation with the CB77 seller in LA. I guess I will be in for another 300 mile round trip to rescue another 1961 CB77 and bring it back to glory again.

The trip and recovery of the 1961 CB77..

It has been raining all of Saturday, with a small break forecast for Sunday, then another wave or rain coming in next week. LA roads are dangerous enough even when dry so maneuvering the Tacoma up and back in the middle of a rainy day gives one pause to think and reconsider my priorities.

SO I WENT ON WEDNESDAY

I had a doctor appointment at 9am about 10 miles from home. I stopped at the local Costco on the way to top off the tank and then make it down to the doctor appointment. It all went well except the 9am appointment didn’t go off until about 9:45. I finally hit the road at 10:15 and off we went some 150 miles up the I-5. At that time of day, the roads are relatively open to highway speeds, at least until you hit LA and then it gets tricky. WAZE had me dodging back and forth on various side streets and highways until I arrived about 1:15.

I backed the Tacoma up the end of the driveway and walked back to Paul’s house and saw the bike sitting beneath a blue tarp. The seat was off and there was an ON-OFF toggle switch mounted on the bracket where the fuse holder normally sits. The ignition switch had no discernible key code numbers on the face, but the rather mangled key that came with the title was a NB series. We did get the bike to fire up for a few minutes, but the fuel in the tank was coming out all brown as seen through the newly installed clear tubing. There was a Li-Ion battery in the battery box and it cranked the engine over with good force, but the lack of fuel finally go the best of it.

Evaluation in person.

I had noted a number of non-1961 features that showed up in the supplied photos, but more came to light as I looked it over in person. I’m guessing that it had a serious crash that left skid marks on the right side exhaust pipe, the little short brake lever was rewelded at the pedal end, there were scrapes on the right side fork slider, the front speedometer drive was not correct for a 1961 model and the fork bridge had little holes on both sides indicating a 1962 part installation. The Scramble-style handlebars were another giveaway and the grips were not the original diamond-pattern pieces.

Over-sized tires were installed at both ends and the front fender was a “Made in Japan” stamped steel unit that is somewhat squared off vs the rounded shape of an OEM fender. The air filters were disintegrating and the air filter tubes were the later type with springs instead of the wide clamps.

The carbs are stock round bowl units. The fiberglass gas tank is fitted with a CB77 petcock and the forward mounts do fit the frame, so it was made for the CB77 originally. Sadly the non-1961 speedo-tach, which showed only 241 miles had a tach needle that spun around and tried to make a full 360 dgree circle when the engine was running. The speedo-tach has a high beam indicator, so is a 1964-ish edition. The kickstarter cover is held in with allen bolts instead of Phillips head screws. The right side cove knob was barely hanging into the damaged cover.

In the bright side, the chain guard was still intact and the tool kit was tucked away in the box. The seat cover apparently was recovered and then chewed on by the family dog. The pan seems to be in solid shape however. The rear shocks should have alloy covers, which are correct for 1961 bikes and the horn is black, as it should be. Most of the cables were replaced so the odd black ones are not present. The frame and engine numbers are just a few digits apart, indicating the factory pairing.

The brief running time on the engine sounded amazingly good with no smoke out the aftermarket mufflers and no terrible sounds internally. The clutch is stuck so will need freshening up with a later model version. The whole engine is covered with 60 years of oily dirt and corrosion, so will need a full teardown and replacement of necessary parts.

WHAT I HAVE IN STOCK FOR IT

NOS wiring harness A&B, NOS Tach cable, NOS fork bolts, NOS re-chromed 1-piece muffler set. Good used OEM fuel tank and petcock. NOS but old Michelin tire set in the correct sizes. Good replacement fork slider for the damaged side. NOS front fender (but steel not alloy). NOS footpegs. A set of solid side covers. A 1961 tail light assembly, which will need to be modified to fit a stock later taillight bracket. I have 10 NOS early tail light lenses! NOS tail light harness wires (white and blue). NOS brake light switch. NOS shift levers and all linkage pieces. NOS pedal pivot bolts. NOS headlight rim. Primary chain.

Missing: The special transmission top cover that wraps around the breather tube. Correct handlebars and cables, plus control switches. Mirrors, of course.

AUTOPSY

With the bike up on the work bench, the parts were slowly peeled off revealing a lot of conflicting issues. Apart from the fiberglass fuel tank and the metalflake blue paint, the headlight shell was pretty much unsalvageable due to extra holes punched into it for extra blue jewel lights. One was for a high beam indicator, as they were not offered in 1961 speedometers. Then, there was the problem with “toggle switches,” one of which was mounted in the little flat plate where the fuse holder snaps in, then another mystery switch mounted on top of the right side ignition coil bracket.

The wiring harness A and B were removed and the headlight shell unbolted. Ebay sellers had some $100 headlight shells available, but careful searching turned up one for $29 that was still in factory primer. All the main bodywork and frame components will be powdercoated black. My favorite painter will handle the Cloud Silver paintwork for the fenders and side covers.

After the air filters were removed, a big surprise was noted in that a cigarette lighter was mounted to the backbone of the frame! More worrisome was that when the battery was removed, it was apparent that a piece of the battery box where it secures the front of the rear fender was missing! I do have a complete frame that could be a donor, although cutting it up for this small piece would be a waste of an otherwise good frame.

Sadly, the rear shocks, which appeared to be in above average condition, apart from the metalflake paint on the tops turned out to have steel covers, not the original alloy parts. As removal continued, the rear wheel has to be removed or dropped down so access to the top rear fender mount bolts can be accessed. The 1961 bikes have an aluminum rear brake stay and this one was still present. Once the fender bolts were removed and the fender set aside, the wheel had to be reinstalled so the bike could be rolled off the work bench for engine removal.

MOTOR REVEAL

With the 115 lb engine removed and up on the work bench, disassembly began. It was obvious that the engine has been serviced previously, as all of the screws were somewhat less difficult to remove than when they are still factory installed. The cylinder head is correct, given that the spark plugs are C9H 10mm versions rather than the later 12mm D8HA plugs used on later models. With the top cover removed, the massive first generation “flywheel” camsprocket was revealed to still be in place. The engine had to be turned over a few times in order for the master link to be accessed. The head was gently pried off and revealed the tops of .75 over-sized pistons and relatively clean valves. When the valves were removed, the seats were wide but intact, showing good contact.

The cylinders were lifted off and a disappointing little rain of broken piston ring bits fell out. Just the top compression ring on the right side piston was shattered. The pistons are the early 9.5:1 types. The wrist pins came out easily and the top end removal was complete. I decided to take the rest of the day off and tackle the bottom end on the following day.

The NEXT DAY

Tackling the bottom end revealed more non-1961 parts inside. The biggest one was that the crankshaft is a later model version with the oil holes in the small ends of the rods, vs. the slotted rod ends used on early model crankshafts. Once the crankcases were pried apart, inspection of the transmission gears revealed a mix of straight and back-cut gears intermixed. The shift forks were rather burned on the sides from previous shifting problems. The gear dog corners were somewhat rounded out, as well. I will probably just replace all the gears with later back-cut types and “X” the gearbox to give the 1-2 gear split a tighter jump from gear to gear. Suprisingly the low gear bushing was in quite good condition and will be reused. The kickstarter pawl was a little worn, as well. I have a number of NOS gears that came from the CO treasure hunt, so the transmission should come out working good. One end of the countershaft’s bushings had a bit of an accident and the locating pin for the bushing got squeezed in a little cocked and there is a small crack in the adjacent support boss. It should be okay with a bit of massaging and making sure that the locating pin goes in correctly.

I bundled up the engine cases, head and cylinders to send them down to the local automotive engine builder shop where they will hot-tank the parts to de-grease the blackend gunk that was glued to the surfaces. I did use some S100 on the engine and frame before engine removal which gave me a glimpse of the condition of the castings. It did have the correct 250 code tappet covers that were leftovers from the dry-sump Dreams. These seemed to be used on the 1961 and early 1962 bikes. They are somewhat domed but have a wide rim around the outer edge. The incorrect right side bolt camchain tensioner will have to be refreshed with the Capellinni replacement sprocket kit. The CL72 oil pump will be ditched in favor of a correct CA/CB style pump with a flat bottom.

In one of those synchronous moments, in the pile of NOS parts brought in from Colorado, there was one package of one set of piston rings which happened to be .75 oversize! That will save buying a box of rings which always come in two sets per engine.

The carbs will get submerged in the ultrasonic cleaner and hopefully will have still-correct and functioning internals. I always check the flanges and then replace all of the o-rings in the carb flanges and the insulators to eliminate air leaks on the intake side.

In the process of removing the camshafts, the point cam popped out of the right side cam. So far, there are no signs of the required snap ring that keeps the shaft in place. I think I have a full set of either new or used cams and a NOS camsprocket to reassemble the cylinder head once again.

In pulling the chassis apart, the swing arm will have to go to the welder for reattachment of the little inside chain guard tab, which is often broken or missing on the older bikes. Because of the alloy rear brake stay, you can’t just replace the swing arm with a later one and have everything look correct.

The next shocker was that the whole front end was not an early model 1961 CB77 with the 38mm fork tubes and steering stem. The updated fork crown was a first clue, but as the forks were removed from the fork bridge and stem, out slide a set of next-generation forks that have a little taper to them vs the big step from 38mm to 33mm on the earliest types. So, apparently the entire original front end was replaced with something from a 1963-ish type bike. That coincides with the front wheel/speedo drive not being 1961 either. So, I’m looking at ¾ of a 1961 CB77 it appears. I noticed that the fork crown holes for the fork tube ends were ground out oversize. Sure enough when I compared a 1961 fork tube with the one on the bike, the OD was increased for the later models. That was a bit of trivia that I had to add to my knowledge bank.

TO BE CONTINUED.

Bill Silver 

aka MrHonda

www.vintagehonda.com

SlowLow350

 Getting referrals can be a tricky thing when it comes to new customers bringing in a basket case bike that was slowly reassembled over a 10 year period. My CL77/160 customer, Jim, from a year or so back, bumped into a guy with a SL350 project bike that he couldn’t get started after doing what he could on his own.

                                               

                                                        Honda SL350K1 courtesy of AHMC

Of course, it was a kickstart-only K1, I think, Orange paint and had the correct black mufflers installed. That’s what showed up when they strapped it to the back of a Jeep and drove 3 hours to meet me at home. I got a quick rundown on what had been done and what had been happening, so based on that information, I decided to check the timing first. The owner had mentioned that the engine had backfired when he was trying to start it, leading me to think that the point cam had been installed 180 degrees out of normal.

As I began to remove the point plate and advancer, I was told that the advancer weight pivot washers and e-clips were missing! With the point plate removed, sure enough the advancer springs were stretched out and the retainer hardware was not in place. Removing the spark advancer, I noted a 369 product code stamped on the advancer base, indicating that it was from a CB360! I dimly recall having a 350 spark advancer that came to me years ago. After a bit of digging, it made itself known and it was marked 312, which is correct for an SL350K1-2. The springs were tight and the point cam in good shape. I added a bit of Bosch point cam lube and dropped it onto the end of the camshaft.

Turning the engine over, to check the valve lash, which is supposed to be at .002 intake and .004 exhaust settings. But the index marks on the ends of the tappet adjuster shafts were all in the 10 and 2 o’clock positions, instead of about 8 and 4 o’clock. The valves had been set on the wrong stroke (overlap), so the actual valve lash was probably an 8^th of an inch. Once the valves were set, and the ignition timing reset after replacing the point plate, it should have been a candidate to start right up.

Unfortunately, all it did was slowly kick over with no signs of life. The plugs were pulled out for inspection and a compression test. They looked dry, even after all that kicking. The engine had never been fired in the last 5 years, so I thought that the cylinders and rings were running dry and not creating a good suction in the intake tract. I mused about the condition of the intake manifolds and was told that they were originals. This could lead to intake air leaks if they are 50+ years old. I dropped the float bowls and found a loose main jet in the bottom of the bowl! I was so glad that they were present to watch me troubleshoot and to witness what I was finding. The next step was to check the mixture screws which were out 2 turns instead of just one turn as specified. I removed the idle jets and made sure they were clear and the float level was set correctly. A number of attempts were made to bump start the bike down the driveway, but all it did was leave black tire marks from the installed knobby tires. Still no signs of life.

What I thought would be a one-hour maintenance visit ran into 3 hours and still no success. The battery voltage was around 10.8-11v, so it should have had enough juice to light off the cylinders. I was running out of ideas and disappointed at the lack of fire in the engine so far. As a last check I ohm tested the spark plug caps only to discover that one was 9.5k ohms, instead of the desired 5k ohms reading. The cap was poorly connected to the plug wire, which wasn’t helping matters. The opposite spark plug cap read out as an open circuit. While we did check for spark with the plugs out and grounded to the head, the combination of BR8ES spark plugs (resistor) and the high resistance on the plug caps were not creating sufficient fire under cylinder pressure. The owner understood what I was doing and what was needed next, so they loaded it back up on the Jeep and headed back to the desert where they were wintering rather than staying in Idaho in January.

Additionally, the kickstarter ratchet was not engaging properly, so the engine was not turning over very much due to restricted kickstarter lever travel. I was sorry to send them off without a running engine, but the lack of parts and other issues prevented a complete success for this pretty, but still sleeping SL350 which has undergone a long Slow/Low 10-year sleep. We all learned a lot about the bike and general maintenance steps needed to make them come alive once again.

With my fused ankle, I was happy not to have to attempt to kickstart the engine this time. I had a similar bike, as part of a 750 swap, some years ago and I recall it was difficult to start up, even when everything was tuned up properly. Give me an electric starter every time!

Bill Silver

aka MrHonda

www.vintagehonda.com