Well, after an arduous 26 days of scrubbing, rebuilding, painting, reassembling and general revival efforts, the 31st 1962 CB77 engine built was fired up late in the afternoon. With paperwork dated back to the 1995 era, the bike easily has been dormant for twenty years or more. With only 2400 miles of use, it obviously saw little use in its life since it was created sometime in mid-1961.
Heavy rust and aluminum corrosion were the main deficits which plagued this particular machine… well that and a seized engine. On the plus side, the bike carried over many of the 1961 features of the first year of Super Hawk production. The main carryover features were the loop-type fork bridge, steering damper design, alloy front fender, small lever petcock, riveted fork bushings, 10mm spark plugs, spring-mount meter set, unique tail light, black cable set (tach, speedo and rear brake), early, un-flanged speedo drive, 8mm headlight shell bolts, large flywheel-style camsprocket, 4-digit lock set, left side camchain bolt tensioner unit and diamond pattern hand grips.
“New for 1962” were items like the top breather engine design, rear frame extensions for seat mounts, lengthened seat pan mounts, silver-painted horn, steel rear shock covers, tail light wiring up the left side tunnel and a steel rear brake stay. As 1962 production ramped up further, some of the 1961 features did change to the next generation upgrades. Many of the 1962 models featured stainless steel mufflers before Honda chose to go back to the chromed-steel units. This particular bike had been refitted with the replacement 1-piece mufflers and brackets, not long before it went into deep hibernation. The mufflers, the higher-rise handlebars and valve spring set (S&W racing springs) were the only major departures from the way the bike was originally produced. The original tires had been removed, so the wheels could be rebuilt and fortunately they were in good enough condition to be remounted once again on the original rims.
The 1961-6 dated wiring harness was reused and is in quite good condition for its age. The ignition switch and fork lock had a key code consisting of just 4 digits (no letters used as a prefix). The correct original keys came with the bike and both lock set pieces are fully functional. Only the dimmer switch required replacing due to damage done when the harness was extended to match the riser handlebars that were installed early in its life.
All the rusted and corroded parts were treated with Evapo-Rust and a soft wire wheel brush mounted on a bench grinder. There was a lot of hand work involved in cleaning various parts which included small brass and stainless steel “toothbrush-type” wire brushes, 3M scrubber pads, small picks and a pocket knife for some tight areas. There are parts which still have the original paint finish left intact, including the fork sliders, fork covers, headlight shell, air filter covers and rear tail light mount. The rear shock covers were painted metal and were heavily rusted. I happened to have a set of replacement plastic Royal Blue shock covers on hand, so they were pressed into service, however after the main rust surfaces were knocked down and neutralized, the shocks went back together with the pitted lower cover and shock damper bodies, as-is.
I didn’t budget a lot of money towards making this bike become serviceable and functional, but the total of parts and services rapidly approached the $2,000 mark (labor not included). Outside services included engine cases being hot tanked at an auto machine shop, welding of the kickstart cover, sandblast and primer on the frame and fuel tank, color matching services and preparation of 2 cans of Royal Blue paint, along with primer and clear coat paints, totaling $350. A nicely made blue seat cover (from Canada) and local foam replacement for the seat, plus powdercoating the seat pan ran that portion up to about $175.
Rebuilding the engine required a $100 piston, $40 ring sets, $90 for gaskets and seals, camchain, oil filter chain, primary chains worth $200, replacement parts for the camchain roller and transmission bushings and offset cotters totaled about $120. New wrist pins and clips were installed in the top end for $30. A correct battery is $60, a box of NLA C8HS spark plugs was $20, then add in $12 worth of Honda GN-4 oil. The engine case screws were replaced with a CB77-specific screw kit worth $30, while the brake linkage rods ran $20 each. A fresh RK-brand drive chain was $40 shipped. New throttle and clutch cables run about $30-40 each, while my reconditioned speedo-tach (courtesy of Foreign Speedo) retails about $185. Ohio Cycle came up with an NOS rear tail light plate for $45 to replace a missing part. They also supplied new acorn nuts and chromed washers for the upper shock mounts and shock bushings, as well. I use their chromed cylinder head nuts and copper washers for the engine, too, which adds another $60 to the tab. Retrobikes offered up reproduction air filters and air filter tubes at $100 for the package. Reproduction kneepads for the fuel tank covers are $115 a pair, plus the little air filter bracket bumpers for $12 per set. Clauss Studios has reproduced a number of CB72-77 specific rubber parts, including the battery tray cushion ($28). The steering damper knob lock spring was $15, so you can see how quickly the parts bills can run up just replacing some critical items on the bike.
Although pitted in many areas, the exhaust system had no rust-through on the bottom seams, which was a big relief as a replacement set like that runs $1000+ if you can find them now. Then you need to source the special flanges, extended length studs and exhaust keepers designed to install the 1-piece exhaust system.
While the color matched paint was dead-on perfect to the original Honda PB-5 code Royal Blue, doing a rattle can paint job left a lot to be desired as far as laying down a nice smooth finish. At least it is all the correct color and looks fairly presentable to the casual onlooker. I did not intend to do a 100 point show bike restoration, due to cost considerations, time constraints and the desire to keep as much of the original patina intact. Much of the original chrome is in poor condition, but the excess surface rust corrosion has been eliminated, leaving it with a slightly up-level “Barn Find” look.
Using the early-style 9.5:1 compression pistons will require careful watching of the spark timing and jetting to ensure that it doesn’t seize a piston due to overheating. The carbs are jetted with #140 mains and timing is accurately set with a dynamic timing light to prevent over-advancing of the spark timing, which is generally the cause of seized pistons. All carb and insulator o-rings were replaced to prevent any air leaks that could lean-out the mixtures at high speeds.
My previous 1961 CB77 successfully ran C7HA spark plugs; however Honda specified C10H plugs originally. I was able to source C8HA plugs from an eBay seller, which hopefully will be a happy compromise for this engine setup. I always run premium gas in any 250-305 engine to prevent pre-ignition or detonation issues. Fuel quality/octane ratings were far different in the 1960s than they are today, so putting the highest octane fuel in these bikes is critical, as far as I am concerned.
The engine did start up after a few dozen revolutions, but sounded flat and was misfiring a little bit on the left cylinder. A check of wet float levels showed them to be somewhat off of what I had set them dry. I had forgotten to reset the left side carb needle from #2 to #3 notch, which was also giving a flat spot on that side. After a full recheck of float levels and needle clip positions, the carbs went back together and the bike fired back up hitting crisply on both sides and idling down to an even cadence as it warmed up. A quick check of the transmission gears, while the bike was on the centerstand, yielded promising results, but the clutch lever pull became excessive when the cable was routed back near the frame. When it was allowed to arc out away from the frame, the lever pull was fairly easy. This a/m cable seems to have stainless steel wire strands inside, which generally means a high-quality cable, but it is acting a bit difficult at the moment.
The -010 speedo drive was successfully mated to the 1961 style -000 front hub, which allowed the use of the flanged drive unit to work in place of the non-flanged original part. The bike was then jacked up in front to allow front wheel removal, required to facilitate the installation of the front fender. This gave me an opportunity to true up the front rim, which had been re-laced with zinc-plated OEM spokes.
The fuel tank paint job came out looking pretty amateurish, but it will have to do for now. I rebuild the early-style petcock previously, so all it took was screwing the petcock onto the fitting and running a long piece of fuel line from the crossover tube fitting back to the matching one on the petcock body. I run the long fuel line over the frame, to facilitate fuel tank removal without all the mess of disconnecting the crossover tube and squirting gasoline all over the bike.
The local upholstery shop missed the Wednesday estimate, but the owner called back to say he would come in on Friday (day after Thanksgiving) and finish up the seat work by late morning. Friday afternoon looks good for its first test drive in over 20 years.
28 Days and Done
The nice gentleman at the upholstery shop made good on his promise to get the seat covered by Friday. The cover came from an eBay seller in Canada, but the end result is that the front of the seat has a gap to the back of the gas tank. It looks like the cover is a bit short, but it could be that the foam installation was excessively high and pulled the front back somewhat. I don’t have time to do anything about it now, so it is what it is. The color seems a bit bright compared to the remnants of the old cover which had an almost metallic sheen to the material, but it seems to be about the same hue as all the other cover kits and seats out there for sale currently.
There were numerous last minute fixes to attend to, prior to an actual test ride. The petcock started weeping at the lever, which seemed a little on the light side for tension on the 4 hole gasket, so the tank was removed and rolled on its side for attention. The early petcocks have a little tab on the spring washer that matches up with the notch on the petcock body, just below the lever opening. I did smooth out the back side of the lever face as it was distorted and etched. Reassembled, it was nice and tight and fuel-proof as it should be.
The used dimmer switch had a wire pull loose at the contact plate, so my spare $100 replacement from Thailand was put into play and works fine. The switch was discolored from sitting in SE Asia for many years, so the finish was a match for the rest of the aged patina on the machine. At least I have fully functioning lights now and the switch out was pretty easy with flat bars on the bike.
The rear tire had a problem where the tube had apparently gotten caught under the edge of the bead, causing the tire to ride up in that spot. Deflating the tube and pushing the stem back deep into the tire before refilling it solved that problem.
Rolling out down the street for a ride around the block proved uneventful, except for some stickiness with the shifter. What seems to be happening is that there is clutch drag, despite installation of a later clutch hub with retainer wires, which is supposed to fix that problem. The original hub wasn’t machined for retainer wires at all. I did reuse the 52 year old clutch disks and have seen lately that they become kind of gummy and have a tendency to cause clutch drag in the last two engines I have rebuilt. An easy fix would be to put a nice 1965-later CB/CL clutch assembly and call it good. I have only put six miles on it, so perhaps the plates will settle down with more usage. I did install some -323- CB500 Four clutch springs, so there is no issue with clutch slipping, but the combination of springs and the new cable have left a heavy clutch lever action so far.
The front end feels rather rigid due to the hardness of the original front tire back in service. There isn’t a lot of “give” to the rubber now, so the forks seem to be slow to respond to the road inputs. With OEM original shocks and tire on the back, the ride quality suffers a bit, as well.
There was some oil seepage along the cylinder head, apparently from the gaskets between the side covers and head surfaces, at least on the right side. On the left side, I discovered that the tach cable was only hand-tight, which left an opportunity for oil to leak out at the cable/drive junction. Even with ancient cables installed, both the speedo and tachometer are working properly. The engine is otherwise oil-tight underneath where the clutch cover often seeps a little bit. There seems to be some contact between the edge of the 1-piece muffler and the clutch cover, which needs some attention.
So far, the bike fires right up, with a little choke applied and idles down easily. It shuts down instantly due to the combination of the racing valve springs and newly installed piston rings. The charging system is still the “high output” version, so is keeping the battery fully charged and making the headlight nice and bright.
Although I may have missed a day or two, the quick and dirty preservation/rattle can restoration efforts proved mostly successful. Starting with a rusty, corroded, stuck engine bike, which arrived with no wheels attached, the ugly duckling has been transformed back into a fully functioning and relatively attractive “rider” bike now. I was pleased to be able to complete the task within 28 days and now the question is what happens to it while I recover from surgery over the next month or so. For now, it will be tucked in beside the W650 Kawasaki, where they will both have a short winter slumber. In a perfect world, the CB77 could have gotten all of its chrome and fasteners re-plated a powdercoat/paint job for the chassis and a myriad of other cosmetic improvements. It is lucky to have gotten this far on a relatively small budget and lots of labor. The bike was worthy of reviving, due to the low serial numbers and the carry-over parts from the 1961 series machines. I know I said it previously, but this really should be the last CB77 project that I am involved with, due to lack of bike parts and aging body parts (mine). Having owned #176 of the 1961 production and this #25 of the 1962 production run, I am happy to have had the chance to get my hands on both of them and learn a lot of those “early days” secrets, which I am glad to pass along to those of you out there who are rebuilding 1961-62 model Super Hawks. They really are fantastic little machines, which even after 50+ years show a lot of style and reliability.