Wednesday, February 17, 2021

Honda 250-305s… pros and cons

 As the alleged “Guru” of the 1960s 250-305cc twins, I have learned a lot about these bikes, most of which has been written into my “Restoration Reference Guides” for each of the three models. In monitoring various forums and vintage Honda groups, I continue to see people digging these bikes out of garages and falling down buildings, just in time to start a rescue project. Usually, the new owners have little in the way of knowledge or reference beyond Honda’s little efforts to create shop manuals. Scrambler owners are surprised to find out that there was no “305” updated version of the “250” shop manual! The CL72 shop manual is a decent place to start but there are no references to the “big-brakes” and alloy forks, so you have to just figure it out by yourself or ask for knowledgeable assistance.

I have owned all of the US-market 250-305s, including a couple of CE71 dry-sump models. I used my first-hand experience with the various bikes owned in the past to compile the reference guides and share what I know with forums and other groups. These bikes have stood the test of time with classic styling, reliability (when properly maintained) and amazing performance and longevity. There were shortcomings in a few areas, which are well-known to most veteran owners, but the appreciation of these well-made motorcycles continues to grow. So, here’s my take on the three pillars of vintage Honda twins.

Engines:

With engines that were lowest in horsepower, Dream engines can last for many years, however, there are features that are shared with all of the 250-305s, which cause problems with higher miles accumulated on these unique machines. Honda’s choice to bury the spark advancer system deep inside the cylinder head in the middle of the camshaft sprocket is a puzzler. Ironically, the CE71 Dream Sports did have a separate spark advancer on the outer end of the camshaft, but when Honda changed from dry-sump to wet-sump engines, they put the spark advancer in the middle of the camshaft.

Problems arise here when the engines have aged and have been ridden higher mileages. The return springs on the advancer weights tend to stretch and loosen, which prevents the weights from coming back to a normal stopped position. The weights also have little bonded stoppers on the ends to cushion the return to rest. These rubbers harden and eventually break off, causing the weights to return further than originally designed. This adds more travel to the advancer weights, which causes an excessive spark advance to come into play. In order to prevent the spark advance from going beyond 45 degrees, you have to retard the idle spark timing back towards TDC, which engines don’t really like. Idle spark timing is best in the 5-10 degrees before top dead center, so setting idle timing at TDC can create rough idle, plus the weights tend to swing out prematurely causing the idle speed to raise unnecessarily.

Spark timing has a big effect on manifold vacuum signals which are acting on the carburetor’s idle circuits. Advanced spark timing increases vacuum signals, which pull more fuel into the engine, which then makes it run faster, so the whole effect snowballs out of control. On a single-carb Dream, the vacuum signals are amplified as two cylinders are pulling vacuum signals alternately.

What else had become apparent over the years, is that the point cams, which open the points at just the right time are not symmetrical on both lobes, often varying 5 degrees between engine cycles. You can watch the spark signals waver back and forth using a dynamic timing light. Another factor that shows up with varying timing signals is that the camsprockets are basically riveted together and after years of enduring camshaft lobes pushing and pulling the camshaft over center each engine cycle, the rivets loosen up, allowing the center camchain sprocket to begin to shift back and forth on each engine rotation. This affects both valve timing and ignition timing, as the parts shudder against each other during engine operation.

The camsprockets can be TIG-welded at the corners to anchor the sprocket to the rest of the assembly, but when the weight pivots wear out and/or the rubber cushions fail, you really can’t remedy the situation, short of replacing it with a new or good used replacement. Adding to the complexity of the situation, Honda changed the camshafts and sprocket spline dimensions through the years, so you must match a replacement sprocket to your camshaft splines. And finally, the camsprockets for Dreams and CB/Cls are different in that the Dreams have a faster spark advance curve using larger, heavier weights that swing out quicker as engine speeds increase. Are you following me so far?

Another note about the engines; they have some wear parts in the bottom end, too. The bronze low gear bushing has a raised center rib to keep two gears apart, but the thrust from the low gear will eventually wear the rib out so it slides off as a separate ring. The kickstarter pawl is in constant contact with the inside of the low gear and eventually wears out causing slippage when kickstarting the engine. The other wear item are the primary chains, which originally were offered in three different strengths, but superseded to the 268 code ones for the Super Hawks. All these endless chains are the same size and length and with over 250,000 engines built, the supplies have dwindled down to next to nothing.

CA72-77 Dreams

Considering Dreams were basically designed in the late 1950s, the basic chassis didn’t change a lot for 10 years. Many of the wet-sump Dream parts share their roots with the 1957-60 dry-sump models. On the plus-side, they were designed to be “Touring” bikes, ones that keep the rider as clean as possible during the ride. Large fenders and enclosed chain guards help prevent unnecessary road grime and chain lube from reaching the rider and passenger. Domestic versions had solo seats and luggage racks which could either be used for hauling materials or with the installation of a clip-on passenger seat, you have a dual rider machine.

All Dreams have the Type 2 (360 firing) crankshaft, which helps give the little single-carb engine a boost in torque, coupled with a lower geared transmission to help move things along The 360 crankshaft firing engine can cause some frequency vibrations that typically cause fractures back in the rear fender/tail light region, due to the sheet-metal construction of the frame. Dreams have shorter cam timing for low-end torque, but run out of breath past 8k rpms due to the single carburetor and cam timing limitations. Dream engines have lower compression ratios than the CB/CL counterparts.

Apart from a lack of horsepower (rated around 24 ponies), the riding experience is hampered by (1. a lack of suspension damping/control at both ends and (2. terrible, tiny, single-leading shoe brakes on both wheels. Other rider complaints center around the “late Dream” (CA78) slide throttle for the carburetor, which has no real return to idle function if you let go of the throttle. Early Dreams used a twist throttle, like the CB/Cls, which allows more control of the throttle function.

Mechanically, for the most part, the Dream engines are pretty much the same. The early model machines used a tall, thin and long 12v battery that was only used on that series of machines and is long out of production. From 1966-onward, Honda retooled the bike to take the 12N9-3A battery used in Super Hawks and lawn tractors. These are much more commonly available, except there are some versions that have vertical posts, vs the flat horizontal posts that the bikes were designed for originally.

CB72-77 Super Hawks

These hotrod “cafe racer” models, which offered flat handlebars a decade before “cafe racer” was a thing, are the star performers of the trio. Early models, with the 9.5 compression engines could hit right around 100 mph with nice big 200mm (8 inch) dual leading shoe brakes to bring them to a rapid halt. Early 1961 models had SLS front brakes (still 8”) and DLS rears for some reason. Honda saw the light early on and switched back to DLS fronts, which were probably some of the most powerful production brakes during that era. The drawback on DLS brakes is that they are very powerful GOING FORWARD. They lose all of their mechanical advantage when the bike is going backwards, however. It’s a somewhat disconcerting feeling to try to hold a Super Hawk on an inclined stop sign/light, when it wants to slowly creep backwards on you, no matter how hard you pull the brake lever in. Most of the time that isn’t a problem, but be aware of the shortcomings of the brake system designs if you come up against this situation; nose pointed uphill at a stop.

With flat bars, the riding posture is leaning forward into the wind, balanced by the air pressure pushing back against your chest. The “flat bar” CB72-77s have “the look” that is a classic pose and mostly preferred over the later 1966-67 low rise bars offered in the US. In actual practice, the low rise handlebars offer more rider comfort for around town riding and for those of us in our advancing years.

My pet peeve for CBs are the stupid friction pivoting driver footpegs and the non-folding passenger pegs. Invariably, as you are shifting the bike around while getting it pointed down the driveway is that the drive pegs brush up against your shins and promptly fold UP and stay UP until you manually push them downwards again. It’s very annoying to be riding around and having to be concerned with the footpeg positions, which are easily displaced from normal.

The rear pegs are solid bars with rubber peg rubbers and if you are standing next to the bike and pushing it around, you will invariably contact the rear pegs with your shins. In the past, I have opted to find the domestic non-folding driver pegs used outside of the US and on CP77s and leaving the rear pegs off, as there is seldom a reason to have a passenger on the back of these bikes

More irritants center around the goofy forward-kicking kickstarter arm. It is either contacting your instep when you are riding and particularly when you are trying to use the rear brake pedal and/or the extended end of the kickstarter arm catches your pants leg and starts to pull you off balance as you struggle to untangle your pants from the kickstarter arm before you tip over in the street. I hate that!

Because of the nature of the spine frame arrangement, dropping the engine out for service is relatively simple, apart from the fact that the engine weighs about 115 lbs. The frame design allows for light weight and responsive handling. The overall vibration levels are much less than the enclosed frame of the CL72-77 Scramblers, under similar circumstances. The Type 1 engine configuration (180 degree crankshaft) gives off a high-frequency, low amplitude vibration that is kinder to the chassis parts, although chain guards and tail lights have been known to have vibration cracks from the engines rocking couple firing. You can watch the rear fenders wiggle back and forth when the engines are idling and the bike is on the center stand.

Super Hawks had distinctively different front fork designs with the early versions made up of steel tubing and ends welded onto the tubes to create the axle holders and the threaded-on fork seal holders. The steel fork tubes can be easily damaged by inadvertent installation of excessively long fender and brake arm bolts that screw into the welded and threaded mounting pads. When the bolts bottom out in the tubing, it distorts the bore shape and the fork bushings jam up inside. The Type 2 forks were cast aluminum parts, with 2 bolt clamps at the bottom to hold the axle and offset bosses to mount the fender bracket. You can tell the difference on a stock bike right away, as the Type 1 steel forks are painted the same color as the frame, while the Type 2 alloy fork sliders are silver on all models.

CL72-77 Scramblers

From 1962-67, something like 80,000 Scramblers made their way to market, mostly in the US. When Dave Ekins and Bill Robertson took brand new CL72s down to the tip of Baja in early 1962, the stunt did wonders for Honda’s sales of their new “dual sport” Honda Scrambler model. Sales skyrocketed in the following years, then really exploded when Honda dropped a 305cc engine in the same chassis. CL77 production ran into about 68,000 units. With the sales successes of the 250 Scrambler, suddenly Honda thought, “Why don’t we make Scrambler versions of all our models?” and so they did. Honda did a bolt-on kit for the CB450 Bombers to make them into “450 Scramblers” back in 1966, before designing a companion model to the CB450 street bikes. There were Scrambler versions of 90s, 160s, 175s, 350 and aforementioned 450s. When the new OHC horizontal 50-70cc engines were produced Honda made CL70 Scramblers. Everyone LOVED the Honda Scramblers for their style and their perceived abilities to go off-road (just a little bit). Certainly, a lot of street bikes were stripped down and raced or ridden off-road, back then, but the stock suspensions were woefully inadequate for serious competition. And it was the same for the 250-305 Scramblers, which had the look, ground clearance and makings of an occasional off-road machine, but really needed some aftermarket help. Japanese shock technology was sorely lacking in the 1960s, with shocks limited to a couple of inches of travel and very little damping capability. That opened up new industries that specialized in improved shocks and fork kits to increase travel and dampening abilities.

The key feature that makes the Scramblers so much different than the Super Hawks is the level of vibration transmitted into the chassis from the engine and exhaust system mounting. Scrambler engines didn’t have electric starters for weight reasons, but that allowed for the frames to have a single down-tube in front of the engine to help strengthen the frame in off-road situations. The closed tube frame design lead to increased vibration transmission throughout the whole chassis, coupled with the long resonant exhaust pipes, which were bolted directly to the frame, caused increases in vibration levels throughout the whole bike.

Scrambler engines are basically Super Hawk engines without the tach drive and electric starter, so all the preceding comments about the engines apply equally here.

Scramblers were always geared shorter for better off-road riding and that lead to more rpms on the highway for long trips. The increased vibration began to cause failures of chain guards and fenders. Because the engine is bolted directly to the frame, all Honda engineers could do was to begin to isolate the rider from the vibration sources. Rubber-mounting of components lead to new footpegs, seat mounts, exhaust system mounts, rear fender mounts, battery mounting systems and even front fork ear cushions to reduce the headlight bulb failure rates. The CL77 rear wheel sprockets lost a few more teeth (37 vs 40 on the 250), as well, because many riders loved the look of the Scramblers, but didn’t always care to go off-road and highway riding got tiring after extended exposures to the vibration levels coming from the engines and being transmitted throughout the whole machine.

With high demand for parts and dwindling supplies, it can easily cost upwards of $10k to do a full restoration of these iconic machines. Most owners opt for the straight pipes with or without baffles or the “Snuff-or-Not” movable exhaust washer accessories. The long pipes have a distinctive resonance that gives them their unique sound.

Bill “MrHonda” Silver



Thursday, January 14, 2021

Highway robbery at the CA DMV…

 Having owned/sold something like 400 cars and motorcycles in the past 55 years, I guess I have been lucky not to get entangled with the DMV “non-op” regulations that can incur big penalties for not paying regular yearly registration fees. A couple of years ago, I let my Jaguar XJ8 get away from me as DMV didn’t send the renewal forms and I didn’t pay attention to the month tag on the car. That was a $100 hit that didn’t sit well with me. But usually, when dealing with 50-year-old derelict Honda bikes, they are generally “out of the system” so that no penalties are incurred because of the lack of registration activity caused DMV to purge the vehicle from their database.

I think a general feeling has been that if the vehicle hasn’t been registered in the last 10 years, that it must be out of the DMV system. Unfortunately, I got a big financial shock last week when I went to register a couple of rather sad, but mostly complete CB77 Super Hawks.

The bikes came from a vintage Honda wrangler up in the LA area, who had amassed about 30 bikes in his garage and back yard, having picked them up in the LA region over the years. The seller had posted the bikes on Facebook forums for what seemed like a good deal, given the 20-foot photos included in the announcement. He actually had posted to the Honda Dream forum instead of the 250-305 or CB72-77 forum, so there was a little less of a response than normal. His location was about a 2-hour drive, each way, from me in Spring Valley, Ca. Having been caught, like everyone else, in the midst of the pandemic catastrophe without a lot to do, I figured a couple of CB77s would keep me busy for awhile getting them back on their feet/wheels and into some semblance of full function and safety again.


The bikes were generally complete; a 1964 still had stock type mufflers, although the left one had a large and long dent underneath and the right side was pretty rusted on the surface and proved to be one of the low-cost Dixie replicas from days gone by. They did both run after a fashion and I was able to drive them up and down the street for a minute or two, just to check out their mechanical function. The bikes were weathered with rusty spokes and rims, cracked cables, faded and chipped black paint and general corrosion on formerly chromed or polished surfaces.


The 1964 bike had a CA plate with 2010 tags affixed. The 1965 bike had an old CA black plate hanging off the license plate ears, but the numbers indicated that it was probably from a much earlier machine. After a bit of wrangling, I bought the pair of bikes, plus a CL77 spare engine that was seized and had an electric starter hanging off of the front and a Dream top cylinder head cover affixed. See previous stories about the mechanical woes encountered after they were brought back home.


Once the bikes had been gotten back to some level of function and safety (after about $600 spent on the basics), I offered them up for sale with “BOS” bill of sale only as I assumed that the guy I got them from had cleared the titles or at least felt confident that they were no longer in the DMV system. Lacking titles is always a crapshoot for anyone who wants to take over a restoration project, so I finally hauled them down to DMV for verification of the serial numbers to start the paperwork trail.

The woman who I have dealt with over the past few years did the initial inspection of the numbers, but then asked me how I knew what the model year was. I told her that I had a lot of experience with these bikes and that often I wound up having to take them to the CHP office for their verification process and that the officer there knew me and knew that I had first-hand knowledge of these bikes and could verify that actual year dates based upon the serial numbers. I have hauled a number of odd or dead bikes to him in the past and with my knowledge of the bikes and showing how I came to those conclusions, he’s always passed the bikes as-is without concerns.

The line at DMV was LONG so I just got the correct forms from the DMV inspector and called CHP to make an appointment for them to check the bikes out. Initially, the first available appointment was 2 weeks out, but I was told to check in early on Tues/Thursday mornings to see if there were cancellations. I called the following Tuesday morning and after overcoming getting no live person on the phone, tried a random phone extension number and got someone to pick up the phone. They checked with the in-house inspector and asked if I could come in at 10AM today! I told them that I would be there promptly and gathered up the bikes to load up in my Tacoma for the 14 mile trip to the El Cajon CHP office. To my surprise, the usual officer that I normally work with was on vacation, so I had to explain what I was trying to accomplish with the bikes and offered a printout of Honda’s CB72-77 serial number chart taken from the factory parts manuals for consideration. After a half-hour, the officer came back and had cleared the paperwork concerns, signing off both bikes as okay to go.

Feeling lucky in the moment, I turned the truck back to the Chula Vista DMV office to see if I could push through the paperwork and get titles for both bikes. Apparently, I caught them on a good day, as the wait time was minimal to get to the customer service counter. A woman there sifted through my various bits of paper, forms, and bills of sale and then checked the VIN numbers in the computer. Much to my surprise and shock, she said that both bikes were still in the system registered to someone other than the guy I got the bikes from in the first place. One had records going back to 1997 for the last registration transaction. That was for the 1965 bike and apparently had been put on non-operation status decades ago, so the “title-only” fee was $61. The 1964 bike, which I had been grooming as a possible “keeper” was a whole different story…


I asked about how long the vehicles stayed in DMV computer records and was told that they can stay in for 20 years! If anyone contacts DMV with VIN number requests for any car or bike, the system captures the request and starts the clock over again if the serial numbers are still valid and stored in the database. Shockingly, the 10-year-old tags on the 1964 bike were never put on non-op status, so there were fees and penalties that came up to a total of $805! When I tried to invoke the DMV rules to override the back fees and penalties according to a website posting that went:

(Always fill out a statement of fact (REG256) with this statement: "I am a collector and this is a collector vehicle exempt from back fees as defined in VC 4604 paragraph B")

5051 collector is defined:

(a) "Collector" is the owner of one or more vehicles described in

Section 5004 or of one or more special interest vehicles, as defined

in this article, who collects, purchases, acquires, trades, or

disposes of the vehicle, or parts thereof, for his or her own use, in

order to preserve, restore, and maintain the vehicle for hobby or

historical purposes.

VC4604 Is the code that describes the non-op penalties, Section D lists the exceptions:

(d) A certification is not required to be filed pursuant to

subdivision (a) for one or more of the following:

Paragraph 3 is the collectable car exception that you NEED to keep in mind and ask for a supervisor if any problem:

(3) A vehicle described in Section 5004, 5004.5, or 5051, as

provided in Section 4604.2. However, the registered owner may file a

certificate of non-operation in lieu of the certification specified in

subdivision (a).

VC5004(a) defines collectible vehicles. Paragraph 3 is the broadest category:

5004. (a) Notwithstanding any other provision of this code, any owner of a vehicle described in paragraph (1), (2), or (3) which is operated or moved over the highway primarily for the purpose of historical exhibition or other similar purpose shall, upon application in the manner and at the time prescribed by the department, be issued special identification plates for the vehicle:

(3) A vehicle which was manufactured after 1922, is at least 25 years old, and is of historic interest.

5004. (a) Notwithstanding any other provision of this code, any owner of a vehicle described in paragraph (1), (2), or (3) which is operated or moved over the highway primarily for the purpose of historical exhibition or other similar purpose shall, upon application in the manner and at the time prescribed by the department, be issued special identification plates for the vehicle:

(1) A motor vehicle with an engine of 16 or more cylinders manufactured prior to 1965.

(2) A motor vehicle manufactured in the year 1922 or prior thereto.

(3) A vehicle which was manufactured after 1922, is at least 25 years old, and is of historic interest.

I was told that while that clause might be valid, my choices were either to pay that amount or pay 10 years of old registration fees at $118 per year. While the clerk was shuffling the paperwork and waiting for my reply, I called the seller of the bikes to explain my plight. The call went to voicemail, but I left a message about my shock and dismay at being faced with a huge registration bill.

With hopes of the chance that I might get some of the money back from the seller, I gulped and offered my debit card to the DMV clerk and she happily hit the account for $805. I offered a few nicely put comments about the unfairness of the penalties, which she agreed with but could do nothing more about the situation. On the drive home, my phone rang and the seller offered to refund half of the amount which was still way more than it should have cost me under normal circumstances, but still was something of an offset.

In hindsight, I should have run the plate and serial numbers in the online DMV system, which allows you to find out what registration fees might be, if the vehicle is in the system. Both my seller and I failed to take the step and the cost was substantial, obviously. So, as has been stated over the years: Buyer BEWARE in these kinds of vehicle transactions… the DMV computers never sleep.

Bill “MrHonda” Silver

1-2021