Monday, November 11, 2019

The Trials of the Trail 90

It should have been pretty straightforward, I thought. I was tasked with reassembling a “project” bike that had been passed along from one friend to another for not much money, a few years ago. The engine was brought to me for a top-end and to un-stick the high-low transfer function of the transmission.

The engine looked like it had been underwater, as the head casting was deeply pockmarked with corrosion and the cylinder bore was rusty. The cylinder was sent out to DRATV for a big bore kit and was reassembled without apparent difficulties. The cylinder head was treated to new valves (aftermarket) but the valve seats seemed to defy being cut in properly. I have both OEM Honda valve set cutters and a partial other seat cutting kit to use, but it seemed that the whole valve guide was offset somehow and the valves leaked every time I reassembled the head.

Fast forward a couple of years and both the engine and chassis returned to me for marrying back together again. There are a lot of little details that seem to take forever to accomplish, but finally it arose from the rusted state towards looking like an actual motorcycle. All the cables were replaced and an aftermarket headlight shell from Thailand was installed with rather poor results as the reproduction part dimensions didn’t fit the headlight rim properly.

Once it was assembled, it failed to start up, despite having most of the ingredients to run. Rechecking the compression revealed only 90 psi, which is marginal for most engines to run at all. The head was removed again and another hour or so devoted to cutting the seats to make a correct seal. After much work, the head was reinstalled and the compression readings came up to 120 psi. It was still difficult to start, but a little bump start down the driveway finally lit it off. Initially, it sounded okay but oil started to leak between the head and cylinder. There is a small rubber sleeve around the only cylinder dowel that feeds oil to the camshaft and rockers, plus a complicated seal that wraps around the camchain tunnel opening.

As a backup, a good used 1969 CT90 head was purchased from eBay seller, but contrary to the seller’s claims, the head was from a CT110, which has completely different head gasket arrangements, plus all of the valve train components were different from the original CT90 types, so that was a dead-end effort.

Researching the engine parts, I noticed that there were two versions of cylinder heads listed for the 1969 CT90, plus apparently some changes to the cylinder, itself, in later editions. I recall seeing the returned cylinder not being the same as the one I shipped out to DRATV, but assumed that they were mostly the same and that we were shipped a cylinder that was already bored and ready to go, instead of getting our original cylinder machined to fit.

When disassembled, nothing appeared to be out of the ordinary or misaligned, but it leaked immediately once again after reassembly. I had parts of another gasket kit with different sealing parts, so I tried those instead, but with the same results. After several rounds of assembly-leak-disassembly went over and over, suddenly the piston was making contact with the edges of the combustion chamber. Marking the combustion chamber numerous times revealed contact up around the intake valve area, just inside the copper head gasket. After a half dozen attempts at carving away material around the combustion chamber, it finally turned over without piston contact.

I contacted DRATV to see if they had problems with piston contact and they said that there were issues, so they include a thicker copper head gasket to move the head away from the piston! They sent one to me at no charge, which was somewhat helpful, but I continued to have the oil leak problems, apparently around the stud knock pin seal. Ron added a bit more complication to the mix when he ordered a set of heavy-duty valve springs and a mild camshaft for the engine, as well. The parts came in with no instructions, as to different valve clearances and if the carb jetting needed changing. I just added an extra thousandth of an inch to the valve clearances.

I ordered an OEM cavity gasket which has an embedded metal base, so it doesn’t squeeze into the camchain tunnel. Finally, I put two sleeve gasket packings on a new knock pin and squeezed it all together. Success, at long last! I verified the ignition timing, which seemed to be suddenly retarded over what it was set to initially and the engine became easier to start and had a much improved idle performance.

There was just one small irritation after another, until I was about to put a torch to it, but resisted the temptation. There’s always a reason for these kinds of problems, but sometimes the answer is not easily discovered, even on such a rudimentary and simple one-cylinder engine like this.

Bill “MrHonda” Silver 11-2019

Sunday, November 10, 2019

Bubble, Bubble… toil and trouble x2

In an effort to find a new home for the Tracy-bodied CB400F, my trip to the El Camino College swap-meet in October yielded a pair of vintage Honda tiddlers, as part of an exchange of vehicles. Outwardly, they looked like fairly intact machines, reportedly both running within the past few months. Well, you know how that story goes…

Exhibit 1. 1967-8 SS125A 125cc twin, showing about 4k miles on the speedometer. Seller claimed to have purchased from an eBay sale and when it arrived and was started up it smoked heavily. One would imagine that the rings were stuck from long-term storage, so a quick top end job might set it right. The right side clutch cover had all the Phillips screws replaced with Allen screws, indicating that perhaps someone had been inside the engine for unknown reasons.

The bike came with a wiring harness in a box, which turned out to be the wiring harness for the bike; not a spare. When the battery cover was removed, the back side of the ignition switch is revealed and it was discovered that all of the connector wires were cut off from the switch. Likewise, the wire ends for the stator connector were cut off, as well. There were two wires leading down to the ignition points connection, instead of just one. The wiring showed signs of newer shrink wrap over the wiring connections, leaving me with a mystery. When mentioned to the previous owner, he said that the bike had been at “Charlie’s Place” in Los Angeles where it was being test fitted for an electronic ignition system. This made more sense, but unfortunately, the project seemed to have been abandoned and I am left with wiring repairs to make. I have a box of misc wiring harnesses and electrical bits, so was able to prune off a couple of matching wire connectors with short leads of wire and patch the cut wires back together again.

I dropped the engine out of the chassis, which is really only held in with 4 bolts. On the bench, the top cover was removed and I was dismayed to see a lack of oil on the cam/rockers and what looked like some heat-related scoring on the cam lobes. The head was removed and mostly just soft carbon was left on the pistons and valves. These engines have little valve stem seals on the exhaust sides, which can harden and then allow some oil to seep into the engine causing smoke.

The cylinders came up next and the pistons were not seized and the rings were all free in the ring lands. Removing the rings and setting them back into the bores to check end gaps revealed little apparent wear on all the parts. I planned to reuse the rings, but noticed a ridge across the top edge of the ring, due to some kind of unusual wear. The 230 code rings are getting scarce and the part number has been superseded to the CB125T model, which uses a 3-piece oil ring set, however that bike was never sold in the US, so parts have to come from somewhere else. I found a salvage business who was parting out a couple of engines, so ordered a used set of pistons/rings, just to get the ring set. Before that, an eBay seller had “CB125” ring sets, which were 44mm but the rings were 1.5mm thick and I needed 1.14mm rings, so those went back to the seller. The set of used CB125T pistons/rings arrived quickly from the eBay seller and thankfully they fit right in. It was interesting that the wrist pins were shorter/lighter than the SS125A versions.

Attention was then focused upon the clutch cover where the oil pump lives. The Allen screws were removed and the cover lifted away. The retainer bolts for the oil pump are secured with a metal strip that has tabs to secure the bolts from backing off. The tabs were in place, but the whole pump was loose on the engine case. Removal of the clutch assembly and oil pump revealed small fragments of a home-made gasket that is supposed to seal the pump to the engine case. Apparently the gasket failed and the oil was squirting out back into the lower end instead of being circulated back up to the cam and rocker arms.

Cleaning the cam and rockers on a soft wire wheel revealed only minor wear marks, so apparently the engine was only run briefly before someone decided that there was a problem with the engine. The cam and rockers were reused, after the valves were de-carboned and new stem seals installed.

A new OEM gasket kit was obtained from an eBay seller, which included the thin paper oil pump gasket, so all the parts were cleaned for reassembly. Not much can go wrong with the oil pumps, as they are a plunger type driven off of the back of the clutch basket and there are two check valves keeping the oil flow going in one direction. I removed the steel balls to clean the pump housing and noticed a thin ring of rust around the middle of the ball where it had been sitting in the same location for years and some moisture in the oil had created a rust ring on the check ball. So, a word to the wise: check your balls before reinstalling the oil pump! These pumps were used on many Honda 125, 150, 160, 350 and 450 twins, so keep this caution in mind if you are having oil pump problems.

The chassis needed new fork seals and boots, new battery, new mirrors, new cables and lever sets. The fuel tank looked to have been coated with a silver coating on the inside, but the outside appeared to have been painted with a brush, perhaps with the same material! The petcock needed replacing, as well. I discovered that the cheap Chinese made petcocks, offered as replacements for the SS125A are not a bolt on fit. The recess for the attaching screw is too small for a common 6mm screw and the sealing washer. The whole standoff for the fuel tubes was too big to fit into the fuel tank opening slot. I eventually was able to get it fitted to the tank, but don’t trust that it will be leak-proof, so bought an NOS Honda petcock for $40 as a backup.

The bike finally fired up after a puzzling event, where the ignition timing was suddenly about 45 degrees off from where I had eye-balled it during the engine build. Oddly, Honda had put two sets of point plate mounting screw holes in the outer cover and when I reset the plate to the previously unused screw holes, the timing lined up successfully.

The engine started up quickly after that, with no smoking at all. A quick check of a tappet cover showed oil flow to the top end in proper quantities. In my excitement to drive the bike, I failed to check the tire pressures and got a flat rear tire about 2 blocks from home! Fortunately, I had a spare inner tube on hand and made the repair easily. The last step was to replace the fork seals and boots with new parts, so now it is a fully-functional SS125A.

The mufflers looked pretty solid at first, but then I noticed that the baffles were gone out of the back sides. The poor little bike seems to have had a rough life in the past 52 years in only 4k miles of travel under its own power. Such is often the fate of these little low-cost machines from the 1960s.

Exhibit 2. This 1971 SL100 that only had about 1300 miles on the odometer. It too, was supposedly a runner, but had been hard to start and keep running according to the seller. The first thing noticed was that there was about 1” of battery acid in the battery. These are battery-powered bikes, so if you don’t have a good battery, it is almost impossible to make them run.

Looking closer at the bike, I saw that the stem for the speedometer was broken off, so the meter was junk. The tires all appeared to be stock originals with little wear. Again, all the cables and levers needed replacing and the left side fork seal was weeping oil down the side of the fork slider. The fuel tank seemed to be relatively clean, but the petcock was rotting away. Both bikes needed new petcocks, which are available online for less than $10 each, but they are, of course, made in China.

The little plastic side covers, which fit all the SL100-125 models, have become scarce and even reproductions are priced over $100 each now. Both are missing from the bike. The headlight rim was taped to the headlight shell with electrical tape which is never a good sign. I ordered a reproduction shell from Thailand and that solved the problem, but the holes for the bolt spacers were too small. It came in black plastic, which I tried to paint with chrome paint, but it didn’t turn out very nice.

After going through the basic tune-up process, the bike initially started up and ran, backfiring back through the carburetor. The ignition points had closed down so the timing was about 5 degrees after TDC instead of 5 degrees BEFORE TDC. Opening the point gap brought the timing into specifications, but suddenly the bike wouldn’t restart despite having all the ingredients of spark, fuel, air and compression. Rechecking the timing with a test light, I discovered that the ignition switch was intermittent, so turning it ON didn’t mean that you had power to the coil in every instance. I installed an aftermarket ignition switch from a CB350, using just 2 of the leads and now the ignition is reliable.

Then engine sounded good once it was running, with no signs of smoke, but the initial ride around the block revealed noticeable primary gear whine in all gears. I drained the oil and pulled the clutch cover to check for obvious damage, but the only anomaly was a somewhat loose clutch basket on the input shaft. The primary gears are straight cut between the crankshaft and clutch basket, so as the load is put on the clutch, the gears fail to mesh squarely, probably causing the noises heard. Honda did upgrade the kickstarter shaft and a couple of gears in these engines, so this one probably needs the upgrade, but I am not going to do it.

The SL100 turned out to be “not on file” with DMV, so fresh paperwork was needed to get a title for the bike, plus a trip to CHP offices for them to do a bit more research on it. The SS125A had a title from Indiana, sold from a guy in Michigan and finally to the LA area seller that I got it from. He had paid some fees to get a title for it, but never got the engine numbers inspected to complete the task. The transaction was still in the DMV system, so I was able to get some of the current charges deducted from what he had paid previously.

ALERT for California residents! When I took both bikes down to DMV, for initial verification of the numbers, the bikes had a few parts missing (SL100-headlight and SS125A headlight, mufflers, tank and seat). I have taken partial bikes to them for the last 10 years without comment, as long as the engine was installed in the chassis when inspected. NOW, all of a sudden, DMV won’t inspect what they call incomplete bikes or “project bikes.” After wrangling with the two inspectors for a few minutes, I left the inspection lanes and took the paperwork inside for my desk appointment. The lady at the desk confirmed that CHP had come down on them for inspecting incomplete vehicles so they made up a new rule to conform to the edict. So, if you live in the Golden State, put all the pieces on your bike before you head down for a DMV or CHP inspection now.

Unfortunately, these little bikes can easily turn into a money pit, once you start replacing even the basic items, like cables, levers, petcock, battery, tires, and other consumables. You better be in love with your new tiddler project, if you plan to embark upon a restoration or even an extensive revival enough to get them fully functional and safe to ride again.

Bill “MrHonda” Silver 11-2019

Tuesday, October 1, 2019

EX-pectations: Kawasaki’s EX500 Ninja

I can’t say that I have really spent any time on one of Kawasaki’s long-running EX500 Ninja models, but one came available on Craigslist that I couldn’t pass up. These bikes were in production for 22 years, with few changes other than adding a rear disc brake, larger wheels and smoothed-out bodywork in 1994.

                                   2002 Kawasaki EX500, 49HP, redline 11k rpm, 426lbs wet.

Wikipedia overview shows:

The Kawasaki Ninja 500R is a Sport Bike with a 498 cc parallel-twin engine, part of the Ninja series of motorcycles manufactured by Kawasaki from 1987 to 2009, with a partial redesign in 1994.

Fuel capacity: 15.9 l (3.5 imp gal; 4.2 US gal)
Fuel consumption: 64.0 mpg‑US (3.68 L/100 km; 76.9 mpg‑imp)
Engine: 498 cc (30.4 cu in) liquid-cooled 4-stroke 8-valve DOHC parallel-twin
Power: 49.9 hp (37.2 kW) (rear wheel)
Seat height: 770 mm (30 in) (1987–1993); 775 mm (30.5 in) (1994–2009)
Torque: 30.9 lb⋅ft (41.9 N⋅m) (rear wheel)
Transmission: 6-speed constant mesh

This bike was a California-emission spec model, so equipped with a carbon canister and pulse air system. The history, from the seller, was that the bike was bought new in 2002 and the original owner had put about 500 miles on before tipping it over and scaring himself from riding it again. The bike sat until about 2012 when it was offered for sale. My seller picked it up, replaced a turn signal, added a new set of tires, a new battery and had the carbs cleaned. He rode it for a total of 2500 miles in the 7 years he owned it, then decided to make space in his garage for new endeavors.

Apart from a little scuff on the left front edge of the fairing and a few scratches on the mufflers and bodywork, the bike is quite nice. When fired up, the engine was clearly not running on the right side at idle. It seemed to run off-idle, but faltered when idling, even after a warm-up. Our shared opinions were that the idle jet was probably clogged up from lack of run time. Faced with having the carbs cleaned again in order to facilitate a good sale, the owner offered it to me for $200 less and I agreed to take it off his hands.

Once it arrived back home, the seat and tank were removed for carb removal/cleaning, however I noticed that there was an emissions vacuum line lying loose near the carburetor. Tracing it back to a junction, it appeared to need to be attached to an engine vacuum source. There are fittings on the intake manifold stubs for vacuum to the petcock on the left cylinder and the right side one was found to be unplugged which is where the vacuum line was supposed to be connected. It all made sense now that the engine wasn’t idling on that side due to a large vacuum leak! I did remove the carburetors and had to reset one of the float levels, but the jets and bowls were still clean, so the loose line was the actual culprit.

With the carbs reinstalled and all vacuum lines connected the bike fired up and ran well. The ergonomics are just about right for my dimensions and I was especially pleased to find out how easily this bike can be pulled onto the centerstand. Ah, the centerstand! This lost relic on many models now, is a treasured feature on street bikes, these days. It makes chain maintenance so much easier and gives the bike a different option to be parked, as well.

While on the centerstand, I turned the back wheel to check the chain slack and noticed that the rear hub has a cush-drive setup which seemed to be worn to me, with a noticeable amount of play in the back and forth directions. With only 3k miles on the bike, it seemed like an odd amount of wear. I ordered a new $60 damper for the wheel but was disappointed to find that a new damper had about the same amount of free play as the original. Apparently, age was not a factor in the old part, but an odd engineering oversight.

Between the gear lash in the transmission and the built-in slack from the rear hub, there is a bit of backlash when on and off the throttle that is attributed to both factors. There is an EX500 forum, with a resident guru who offers a few improvement bits and sage advice. His suggestion was to add in some pieces of an aluminum can to pack in around the damper, in order to tighten up the assembly. He also offers some rear suspension dog bones that raise the rear end about 1.5” in order to change the geometry enough to eliminate some odd handling quirks in these models. However, jacking up the rear end negates the function of the center and side stands, without carrying some stand assistance pieces onboard. Carrying around a 2x4” board in your backpack might be an option for some, but I would seek other options, personally.

I noticed that when I reinstalled the rear wheel, the right side axle adjuster tended to squirm around when the axle nut was tightened. The only way around it was to tighten the axle into the nut with the provided tool kit wrench. Yes, these bikes do seem to have a few quirks, despite their lengthy development time. 

Closer inspection of the rear axle setup revealed that there was a gap between the rear caliper bracket and the inside of the swing arm as you go to tighten the axle nut down. I found a 1.5mm shim to slide into the space and that seemed to help out quite a bit. There’s no reason to be pinching in the ends of the swingarm just to tighten up the rear axle hardware. So far, the bike has been up to an indicated 95 mph with no problems in the handling department.

The other puzzling issue was that the rear brake pads were worn quite thin. I ordered some EBC pads online and they installed easily with 3x the thickness of the originals. The front pads still seemed to have decent amounts of material left, so I guess the previous owners were rear-brake oriented.

Overall, the bike is really pretty good. It has a few more rated horsepower than the manic CBR250R that I ride, but weighs about 75 lbs more in wet weight. Obviously, the 500 twin has more torque and is geared higher for more relaxed freeway cruising at half of the engine speeds as the 250-4. Both have been getting close to 60 mpg, so quite economical to own and enjoy.

                                      1988 CBR250R (18k redline, 45 HP, 350lbs wet)

The only Kawasaki motorcycles I have owned in the past were a 1984 GPZ550 and a trio of 2000-2001 W650 twins. They are solidly-built machines with numerous positive attributes. Even though it seems out of character for MrHonda to own bikes from the K-brand, I think it is healthy to sample and appreciate bikes from other makers, especially when they bring a strong sense of satisfaction to the riding experience.

Bill “MrHonda” Silver

Tuesday, August 6, 2019

Grime and Punishment…

I’ll be the first to admit that I HATE to clean old motor parts, especially scraping baked-on asbestos gaskets on the old 250-305 engine series. I have spent about 10 hours of my life in those pursuits just in the past few weeks and I am TIRED OF IT!

After completing a CB77 engine recently, which was favored with a vapor blasting job, I reluctantly agreed to do ONE MORE engine overhaul on a 1964 CL72 engine. It was delivered on a homemade engine stand, which was handy for initial tasks that included tear-down of the top end and loosening some engine case bolts. The entire engine was basically an abused mud-ball of clay dirt, baked and sealed into the open aluminum pores which are so prevalent on the many sand-cast engine pieces. This turned out to be one of the most challenging engine rebuilds I have ever done, due to the outside grime and the inside baked-on varnish, which only comes off with physical scraping. It was awful….

At least it turned over, but getting many of the screws out was a test of patience and endurance. The engine task included a total of three engines from which to choose the best parts for the rebuild. The customer told me that it would need a good cylinder, due to fin damage and probably a cylinder head, as well. Not until I got the head off that the magnitude of a previous attempt to remove the head made itself known.

The owner’s “helper” attempted to remove the head without disconnecting the camchain, apparently thinking that the engine was a push-rod twin, perhaps. When the engine was viewed from the right rear, it was obvious that someone had broken several of the fins in a misguided effort to pull the head off. When I disconnected the camchain and removed the head, I discovered huge gouges in the edges of the cylinder head surface and the top of the cylinder block. That damage was fresh, but it became obvious that the top end had been rebuilt once before, as there were .25 over-sized pistons installed. Apparently, the correct 54mm head gasket was not readily available at the time of the engine build, so the previous mechanic just placed a 61mm 305cc head gasket on the cylinders and put it back together again. The baked-on varnish, a result of years of sitting on the internal parts after being severely overheated were so gummy that the transmission shift forks wouldn’t move because of the varnish build-up between the two forks on the shift drum.

A reconstruction would require a good replacement head and cylinders from another 250cc engine. Fortunately, my friend, Ron Smith, happened to have a spare CL72 engine that had been an inhabitant in his garage for the better part of 10 years. We arranged to have me pick it up from Ron’s Pacific Beach home and the lump was deposited in the rear of the shop area awaiting the needs of the customer engine.

Both of the CL72 engines were packed with mud, hardened old grease and varnished innards due to lack of engine changes and/or engine overheating of the oil back in its history. The customer engine’s internals appeared to be fairly clean and unworn as far as the cams and rocker arms were concerned. Once the head was disassembled, the cam sprocket showed signs of loosening rivets, however, so that would either have to be welded or replaced with a known good part.

Ron’s engine was pretty much fried inside, with well-worn camshaft lobes, rockers and a lot of varnish inside. Apart from one cracked fin on the cylinder head, the head and cylinder block were sound, but filthy full of dirt and grease. Wouldn’t you know that the “last one” would be the worst one to clean.

The customer engine also had a chunk missing out of the bottom case, back below where the countershaft sprocket is located. I still had the remains of a 1962 CB77 bitsa engine, which had a good bottom case, so that engine was cracked open to donate a few parts, including the bottom engine case half. Some ill-advised mechanic had put the engine together with orange RTV silicon sealer, which adhered to everything, requiring patient residue removal efforts.

The customer engine showed signs of some bottom-end work, judging from the condition and type of fasteners used. Careful inspection showed that someone had swapped in an earlier model transmission gear, which used straight-cut gear dogs instead of the later type, that used back-cut, angled gear dogs. The whole low gear bushing had the separating ring worn off and the kickstarter pawl was severely worn down, where it contacts the inside of low gear.

The gear dogs were worn on the drive side due to a lack of proper gear dog overlap which caused the transmission to jump out of 2nd gear. Signs of its struggle were also seen on the high point of the shift drum where it engages the fork that drives 2nd gear. Offset gear cotters were installed, along with new 14mm shaft bushings on both ends of the layshaft. One end bushing was severely worn where the kickstarter pawl was digging into the bushing for many miles. The other end bushing which helps to contain the rollers had a crack in the edge. That was a very unusual part to suffer damage from my experience.

Fortunately, I have a storage bin full of used transmission parts, so sifting through the pile turned up just what I needed to put a good transmission back together again. The last little trick was to X the gears, which closes up the gear gap jump from 1st to 2nd gear. The 250 engines respond to this modification well, as they lack the grunt and power of the 305 models.

The customer engine came without anything installed in the kickstarter cover, so I had to dig out a kickstarter arm and pin from my stash, a knuckle, clutch lifter/adjuster and return spring setup from Ron’s engine. The remaining parts came from eBay which came to about $35 for just a handful of clips, springs and a ball bearing.

The engine casings and top-end parts were repeatedly cleaned in various solutions, including a pass with some oven cleaner, but much of the embedded dirt needed direct removal using a combination of rifle brushes, rotary brushes, stainless steel wire brushes and small pointed metal tools to get down into the nooks and crannies of these complex engine castings. I generally do not paint these engines, apart from the clutch covers and kickstarter covers, but I am probably going to make an exception to my usual practices, in order to brighten up this grubby little motor. 

Unfortunately, both of my “cleaning” resources were unavailable, so I wound up spending over an hour on each one, just to get them close to presentable. I had to clean two different clutch covers before I was able to use one with confidence, but that one needed some JB-Weld repairs for a small dent just below the oil filter cover area. Even the outer filter cover got a patch to cover some road damage. Every one of the filter covers I had in stock was damaged almost exactly the same way and place. The right side dyno covers are also NLA these days, but the solution was a $95 billet cover made on a CNC machine.

The cylinder head from Ron’s spare engine received all new valves, once the seats were cleaned and cut fresh to make a good valve seal. I was surprised to discover one VERY loose fitting intake valve in the head due to a worn valve guide. I have had valve guides floating around in my spares for years, as they seldom go bad, but I really needed one this time! Once I coaxed the new guide in, I had to clean it up with a valve stem reamer, then re-cut the seats again to match up with the new valves.

The customer cams and rockers were reused and the best of a couple of sets of valve springs put back into the engine. I have found that you have to check the valve springs carefully, as one had the end broken off. A near-new cam sprocket was discovered in the parts bins, which had matching spline patterns which took care of the problem of the loose rivets and floppy return springs.

All new chains will be installed, including primary chain, oil filter chain and camchain. I get the primary chains and oil filter chains from a vendor in the UK, which is great because the OEM parts are NLA and extremely expensive if you do happen upon any of them now. I replaced the camchain guide roller with one from CMSNL, which reproduced them recently.

The most expensive part of the engine build would have been a $200 NOS camchain tensioner, which seems to be one of the last remaining ones on the planet. With some digging, I was able to purchase a usable camchain tensioner for $15 on eBay, so the new one will be resold or swapped for something else, perhaps. I had a NOS D.I.D. endless camchain in stock, so decided to assemble the engine with that. 

Ron’s cylinder block was still on STD bore, but there was some rust in the cylinders, which required a first overbore to match some pistons that I had left in stock. Stock CB72 pistons, used in the CL72 engines have a pretty high dome anyway, even in the lower 8.5:1 compression versions. My spares are the 9.5:1 versions, which will give it a little extra kick.

It seems like my self-inflicted punishment for not stopping the rebuild process, after the last CB77 completion, is being tethered to a solvent bucket and scrub-brushes to clean the grime from all these parts, one piece at a time by hand, which is a most unpleasant task at my age. After this one is complete, I declare “Enough!”

Bill “MrHonda” Silver 8/2019

Sunday, July 28, 2019

Stuff I’ve seen… stuff I haven’t seen

In my current (and hopefully last) Honda 250 engine build, I am in the middle of piecing one good engine from 3 engines in total. Two of the three engines are CL72 250cc twins from 1964-5 and a 1962 CB77 engine that was leftover from the last 305 engine build.

In the middle of all the current mess, I received a message from a SoCal CL72 owner who was having difficulties in getting the kickstarter to operate correctly. He had a local shop tear down the bottom end to have a look and this is what they found…

In all my days of dealing with the 250-305 engine group I have never seen a kickstarter shaft snapped off like this one was. More damage photos followed:

Low gear bushing ground away inside and the shift shaft splines twisted at the end… on a bike that had 5k miles, according to the owner. Wow! The parts bill for everything he needed was $350 alone.

Fishing through the three engines, here in the shop, revealed more disasters in the making. The 1962 CB77 engine didn’t come with a primary chain tensioner, but this one had a lower case change to include that feature. The bottom engine cases are mostly interchangeable, so fitting a 1963-on lower crankcase half was a good idea. The REALLY sad part of this engine was that it was fully assembled with orange RTV sealer on all gasket surfaces and the engine case halves! For those who think this is a good idea, I just have to say NO, NO, a THOUSAND TIMES NO!

In dividing the various transmission shafts up for inspection, I found a low gear bushing with the center ring floating inside low gear, a kickstarter pawl with ground down ratchet surface and the substitution of an early 2nd gear, which has straight cut gear dogs installed to mesh with a gear that had backcut gear dogs. I can’t say that I have seen this bushing cracked like this, either.

The hat-shaped 14mm end bushing had deep gouges in the surface from the kickstarter pawl contact and the gear dog overlap was less than 10%, with wear showing on the edges of the gear dogs from jumping in and out of 2nd gear. The shift forks were worn and old varnish deposits caused the shift drum to hang up inside the shift forks, preventing easy shifting of gears. The shift drum retainer plate had cracks in both screw holes and the forward kickstarter shaft bushing had a crack along the trailing edge.

Based upon general observations in the past 30 years of working on these engines, I would put the suggested parts lists to include:
*Low gear bushing, especially of the center ring is worn loose, as above!
*Kickstarter pawl, including the spring and plunger
*Kickstart shaft, if the roller bearing surface is damaged or the splines are twisted
*14mm end bushing
*Offset gear cotters ( 2 or all 4)
*Shift forks (reuse good ones)
*Shift drum (reuse good ones)
*Shift fork Roller bolt locking tab washers 2x
*Crankshaft locking tab washer
*6mm sealing washer for that long nut on the bottom case.

If the transmission has been jumping out of 2nd gear, then make sure you match the correct gear(s) for the rest of your transmission’s requirements.

If you look inside the top of the clutch cover and see a small shiny spot worn into the case housing, then the primary chain has worn beyond limits. If the primary chain is worn, probably the oil filter drive chain is also worn excessively. Replace both items. Aftermarket replacements are available from UK vendors.

Be aware that most of the basic return gearshift transmissions all use the same basic shifting selector parts, so you can go fishing for what’s needed outside of whatever model you have now. There are differences in the old/new CB/CL transmissions, including a late 1966 change in the spline depth. Dream transmissions had very few changes, but you can’t intermix Dream and CB/CL transmission gears.

Shift drum roller, locked up in above photo, lead to wear on the roller and arm just below the roller rivet pin.

Remember that all the transmission and shift selector repairs can be done with the bottom end of the cases split. You don’t have to tear down the whole engine to do lower end work. 

While you are in there, check the condition of the neutral switch. Many have broken wire connections or all full of dirt/grease and can’t make the required ground connection to turn on the neutral light. Check function of the switch before you put the kickstarter cover back on.

Bill "MrHonda" Silver 7-19

Thursday, July 18, 2019

And so it begins again… will the CL90 circle be unbroken?

It was my very first motorcycle; a 1967 Honda CL90 Scrambler 90, which turned up at a local used car lot, apparently traded in by a local serviceman. I don’t recall how I got the money, but I think the price was about $350 and suddenly it was MINE!
You may have read the saga of my 1500 mile journey on the little Scrambler 90 in just 3 days. I began in San Diego, riding up the Hwy 395 eventually to Reno, then back over the mountains, out the I-80 to Sacramento and San Francisco then down the PCH until I hit Playa Del Rey, CA.
The bike seemed capable of somewhere around 60 mph and it was ridden at pretty much full-throttle for the whole trip. I stopped every 100 miles and put in ONE gallon of gasoline, then off I went again. I did virtually no maintenance to it, apart from keeping the oil level topped off. It just ran and ran and ran…
Having run through something like 400 cars and bikes in the past 50 years, I have seen a few decent examples of the little Scrambler, but most were in a rather poor condition with worn or missing parts and generally lacked decent care. I don’t actively seek out my “first bike” these days, but one pretty good example came my way via a phone referral from nearby Carlsbad, CA.

I was puzzled, at first, in that the bike had most of the CL90 parts, however, it had a S90 fuel tank mounted up in place of the little Silver Scrambler tank that one usually sees on a CL90. The message sender came back with “I liked the looks of the S90 tank, so I put one on the bike. I still have the original CL90 gas tank, though!”
The bike appears to be a 1968-69 edition, which featured chromed fenders, turn signals and the little front fender reflector, unlike my plain-Jane 1967 machine, which probably came from Okinawa. The bike didn’t have any turn signals and the fenders were painted Cloud Silver, just like the tank. Honda 90s were no strangers to change, although the main CL90 chassis appears to be interchangeable with an S90, there were CL90-specific parts used to differentiate the two models. The fenders, seat, muffler, fuel tank, and handlebars were the principal differences. Mechanically, the two were mostly the same beneath the cosmetics.
I happened to be in that part of the county, last week, so arranged to see the bike and perhaps take it home…
In all of its “glory,” the bike sat at the opening of the 2 car garage, awaiting inspection and/or purchase. It’s funny how the first impressions, felt in the gut, will give you a feeling of attraction or repulsion and unfortunately, the latter came into full force almost immediately. The list of deficiencies ran long, right from the beginning. Most all of the chrome was pitted to some extent and the bike hadn’t been started for quite a while. A lithium battery was installed and had enough charge to light up the neutral light, but a few kicks gave no joy. A check of the fuel tank revealed nothing inside. I did bring a compression gauge and got readings of 150 psi, which was hopeful. The miles showing were about 1500 and appeared to be original.
Among the missing were: chain guard, battery cover and center stand. The original CL90 fuel tank was in a separate box and there were telltale dents on both sides at the front edges. That usually only means one thing… steering stops on the frame sheared off from a crash. The end of the throttle grip was torn and the rear brake pedal was bent upwards beyond the footpeg, all indicating some forceful damage due to a crash at some point in its life. The bike had an original CA “Black plate” which are revered in the Golden State as being original to the bike and seen on all cars until about 1969. Unfortunately, the bike had never been registered to the seller since he took ownership sometime back in the 1970s.
Right before I left (Sorry, I have to pass on this one), I checked the serial numbers and discovered that the 2XXXXX numbers on the frame were not backed up by the engine numbers, which were 1XXXXX instead. There were a lot of Allen screws installed in place of the normal Phillips head screws, so someone had been doing some kind of repairs or just installed a different engine. Both were CL90 series though, instead of an S90 engine transplant which is often more commonly seen in situations like this.
With only the one photo to go from, I couldn’t tell just what the “value” might be. The seller put out a feeler at $1,000 initially. In an ideal situation with a near mint bike, the price might have been supported, however, this one was far away from that kind of price range. I felt that something in the $400-500 range might be more appropriate, given the condition and the many needs of this little Scrambler. I offered to help him sell it and posted photos on Facebook forums that evening.
I forwarded three potential buyers to him and one apparently showed up and paid $700 for the bike and was excited at the prospect of getting it going and maybe doing some level of restoration to it over time.
So, in the end, it was not my time to revisit the “first bike” scenario again and that was probably a really good thing, as my time would be sucked up in a fruitless labor of love, which would reduce my customer repair time, where I actually do make a little money these days.
Well, no doubt, there is something else waiting in the wings for me and my little envelope of cash leftover from the sale of the Honda Reflex scooter. In the meantime, the “Unique CB400F” bike featured in previous posts is getting revamped back towards stock again, but with a few little twists to make it a little more “cool.” Stay tuned for that update.
Bill “MrHonda” Silver
PS/// Same bike showed up on CL for $1500 asking 2 days later...

Sunday, July 14, 2019

The JDMs in my life…

In more than 50 years of Honda motorcycle ownership, bikes of all sizes and histories have come my way, with the bulk of them “normal” US-spec models. I have owned more than a few JDM (Japanese Domestic Market) Hondas, which have mostly just showed up unexpectedly. It is an interesting mix, starting with the oldest ones… a 1954 90cc J model Benly and an F Cub, the Honda 2-stroke powered bicycle and they just kept coming…

I turned up the J Benly at a local salvage yard, which was sitting for many years before I extricated it, more out of curiosity than anything. It was rough, but mostly there, but the kickstarter cover had been split and re-welded once. I disassembled the engine just to see what was inside and did a valve job on the cylinder head, using a CB750 valve guide.

Ownership of this bike actually started my involvement with the VJMC, as I was trying to contact others who knew anything about this model at all. I sold the bike, locally, to a friend who sold it to Brian Slark (Barber museum wrangler) and it wound up in St. Louis for a number of years. Mike Buttinger contacted me looking for an “old Honda” and I put them together. The bike was shipped to the UK where it underwent a 100% stunning restoration, subsequently winning a “Best of Show” award at Staffordshire. I did, briefly, own a JC58 Benly, back in the 1990s, but sold it off before it was running again.

The “F Cub” might have actually been older, perhaps a 1952-3 edition, which I purchased off of eBay right after I moved to Hawaii! The bike was shipped in a bicycle box and arrived safely, from many thousands of miles away. It was a fascinating look into Honda’s first in-house engine building efforts, but wasn’t going to be practical for the Islands, so it was re-sold on eBay to someone in TX, who flipped it again, not too long afterwards.

My first ever motorcycle was perhaps a version of a JDM, probably from Okinawa. It was a 1967 Honda CL90 Scrambler. It was brought into the country by a local sailor, I think and traded in for a car at a used car lot. It was definitely the only one in town, as even the local Honda dealer had no idea of its existence. They were released in the US a few months later. That bike is the one that I drove 1500 miles in 3 days, going from San Diego to Reno, NV, to SFO and then back to LA, getting 100 mpg all the way.

The only JDM that I went to fetch in Japan, was an early SS50 Sports 50, featuring a 5-speed gearbox connected to a 11,000 rpm motor. That bike went 60 mph right out of the box. I was in the USAF and flew from my base in Sacramento to Yokota AFB in Japan, visiting Curly’s Honda, just outside the base entrance. I picked out a cute red SS50, paid $175 for it and was told to come back later. Upon my return, I found the bike had been turned into a neat pile of perfectly wrapped parts, suitable for shipment back on the C135 jet plane, as I returned back to Sacto, via Fairbanks AK.

After my stint in the USAF, I returned to San Diego and bought/sold a lot of Honda bikes. In the late 1970s, I happened to be in the UK, when Honda released the 1977 CB125T twin to the local market. I had been roadracing on and off since 1974, in the 125 Production class, so thought that this bike would be more competitive than my series of CB 125S models, which were all that was available in the US. The CB125T was another out-of-the-box terror… 80mph at 12k rpms in totally stock condition. The bike was raced successfully at several tracks, including Ontario Motor Speedway where it hit 88 mph at 13k rpms drafting a 175cc class bike.

I went back to the UK a few years later and discovered the new 1980 CB250RS street bike, based upon an XL250 chassis/engine, but with alloy rims, disc front brake, improved engine and a tiny quarter fairing. That bike would run up to about 90 mph and got 90 mpg at the Craig Vetter Gas Mileage run in 1980. I sold the bike to buy a new VF750F Interceptor. About 30 years later, the same CB250RS showed up on Craigslist, here in San Diego.  It had about 28k miles on it and was still owned by the same woman who bought it in 1983. It needed waking up, but it ran fine after a bit of work. The engine had never been opened up, wasn’t using oil and didn’t leak.

A rare CBM72 250cc Super Hawk (Type 2 engine with 360 crankshaft) showed up on a local Cycle Trader listing in the mid-1980s, which was the first of that type I had ever seen. I also pieced together a Type 2 CB77 domestic bike, during that time which had a lot of CYB racing parts installed on the chassis. I sold that bike in 1988 and wound up buying it back from the estate of the owner in 2017.

In the late 1990s I came across a CP450 for sale in the Mid-West. Apart from an oversized windshield and a dual seat, the bike had most of the CP parts still on it. I was able to purchase it and have my local wholesale friends grab it for me and haul it back to San Clemente, where I lived from 1996-2001. I was able to buy a NOS solo seat and rear rack directly from Honda. There were only 25 of the all-white 4-speed Black Bomber models brought into the country and Honda did inventory parts for them. 

Through a rather complicated purchase and swap, I did wind up with a rare CYP77 Honda 305 Police bike, all in bits. They were never offered in the US (some CP450s came over in 1965), but a few were sprinkled around in Canada, which is where this particular bike was sourced. I found an ad, somewhere on the Internet, I think, where two were being offered. I gave the information to a friend in TX, who was seeking a project like that and a year or so later, the first one was finished to perfection. Enough parts had been rounded up to do the second one, but his enthusiasm waned. After sharing photos of the first one, I asked about bike #2 and he offered it up for trade wanting a CB92 project instead of cash.

I had just moved to New Mexico, but had been in contact with a man who had an unidentified “Benly” out in the desert that he wanted to sell cheaply. It turned out to be a CB92 with a unfinished CB160 engine wedged into the chassis. The bike came with the original engine, YB racing parts for the Benly and a YB seat for a CB77, too. I had to make a 1400 mile round trip over the weekend to fetch it all and return to NM. On Thanksgiving Day weekend, my friend drove up from Houston with the CYP77 and a running 1967 CB77 to swap for the CB92 project. I built the CYP77 in about 3 months and then sold it to CMSNL in Holland, prior to moving to Hawaii in 2002.

In 2017, an avalanche of JDM bikes came to me in convoluted ways… First a CB77-styled domestic CB350 went up for sale in PA, but the bike had been partially restored by a friend in NoCal, a few years earlier. I bought the bike and had it shipped here in SoCal, where I brought it back to life, but discovered numerous issues that needed a lot of TLC. At the same time, a 1997 Honda Dream 50 street bike came on the market, in Indiana, from a good friend and enthusiast, who had a lot of experience with Honda 350 twins and we wound up swapping bikes back and forth to the Mid-West. The domestic CB350 had gone from N. Cal to PA to CA and back to IN, in the space of a year.

In the meantime, the man who transported the domestic CB350 to me also had brought in 24 JDM-UK bikes from England, earlier in the year, including a 1988 CBR250R 250-four cylinder bike, which has a redline at 18k rpms. On the way back to CA, while bringing in the 350, he picked up the 250-4 from his warehouse in Oakland and brought both bikes down to me. The CBR250R was a little bit rough, but ran well and was great fun to drive. I had just gotten it registered in CA when ANOTHER 1988 CBR250 showed up on eBay auctions. The bike had been brought in from Japan by a dealer in Utah. That bike only had 310km on it… about 185 original miles and had been serviced and titled in UT. The first CBR250 was sold to an enthusiast in LA and the “new” bike remains with me today with about 1200 miles on it now.

This interest in more modern JDM models lead me to bid on a 1989 Honda NC30, which is the 400cc V-4 version of the fabled RC30 750ss Sport bikes, which are now fetching $25-50k. I didn’t realize it, but the seller was the same guy I bought the first CBR250 from! It took him a few weeks to bring the bike out to SoCal and unfortunately there were numerous problems that were not disclosed in the auction, including having the original carburetors replaced by some “parts bike” carbs of a different series that had damage and missing parts. The fork seal on one side was leaking a lot and the bike tried to bend a rod by trying to compress a cylinder full of raw gasoline that had leaked into the cylinder through the vacuum hose attached to the vacuum operated petcock.

A new OEM Honda petcock diaphragm kit fixed the tank problem and I learned to turn the engine backwards to purge out the gasoline back into the exhaust system. I’m not sure why it didn’t catch fire and/or blow up once the cylinder was cleared and the engine fired up for the first time. I did get one ride in on the bike for about 75 miles before tearing into it, in an effort to salvage the carburetors. With 60+ horsepower and wet weight of about 400 lbs, the bike is quite entertaining to ride, once it clears its throat. I am hoping for good things from it, but it is going to take a lot more time and $$ to get it close to right again. I actually sold it on eBay to a guy in Hawaii, so the bike resides over there now.

I think that this will be the last of the JDM Hondas to come my way, but as you know, life is just FULL of surprises.
Bill Silver