After a lot of fancy buying/selling of CB77s this past month, I was offered a “restored in the 1970s” CB77 that was supposedly built with a WEBCO 350cc kit and the Harmon-Collins roller rocker camshaft kit. I was excited to fire it up, after receiving a new battery and cleaning out the carburetors. (See previous stories).
The bike came down with spare, used clutch cover and kickstarter cover, as the ones on the bike were chromed and the seller said that the kickstarter would need a “new gear,” so it could be used in kickstart mode. The extent of the “modifications” were no immediately realized or relayed to me at the time of the sale. I was sucked into the mystique of the WEBCO/Roller cam syndrome which I have never experienced as a vintage Honda enthusiast.
After a relaxed walk-around the bike I noticed that the kickstarter cover had been trimmed back towards the rear edges and that there were NO holes present for the kickstarter shaft gear nor the intermediate kickstart gear in the cover where they normally belong. Initially, it seemed that the engine builder just covered up the outer edges of the holes and that there would be a k/s shaft sticking out when the cover was removed. WRONG! The kickstarter shaft had been cut off flush with the outer edge of the shaft seal! Normally this is a BIG NO-NO as the kickstarter shaft is supposed to be anchored in place by the kickstarter mechanism. Failure to anchor the shaft leads to the kickstarter pawl being actively engaged and allows the shaft to rotate back and forth.
I had noted previously that there were no signs of the WEBCO oiling hole modification, which is suggested to help lubricate the piston skirt and that the point cam had been installed upside down. Obviously, the engine was going to have to come out and have corrections made wherever necessary. So, instead of firing up the monster bike on the 4th of July, I was pulling it out of the chassis and tearing it down for inspection, repairs and any modifications.
Not only did the builder modify the k/s cover and cut off the shaft, they also trimmed off the little ear that sticks up through the whole in the transmission cover, PLUS they cut off the screw mounts for the rear anchor point for the kickstarter cover. My confidence was waning as I continued to work on what was hoped to be a very special CB77.
Once the engine was removed, the removal of the top cylinder head cover was the first order of business. The cover came off well, but then the modified baffle plate, with a gasket on both sides, was well adhered to the cylinder head surface. Prying around with a Swiss Army Knife and then a long gasket scraper finally allowed the baffle plate to be removed but destroyed the gaskets. The baffle plate gets some serious dents put into it due to the size of the rocker arms and the valve lift generated by the camshaft profile. A look down the intake ports showed some signs of porting work. Someone was trying to make something special out of the CB77, but it looks like they fell short of fully realizing their goals.
The cams and rocker arm rollers all appeared to be in very good condition. The camsprocket assembly was welded up to prevent the cam gear from working loose at the rivets. The big mistake was that they failed to index the point cam properly when they drove the camshafts together on the right side. The point plate had been installed upside down to compensate for the point cam mishap, which is functional but not very professional. At first, it appeared that the head gasket was coming off intact for reuse, but as it was removed, there was an obvious blow-through at the fire ring on the inner edges, mirrored on each side at the same location. THAT’s going to be a problem!
The clutch seems to be a Barnett unit but didn’t have the retainer springs installed. The transmission gears all looked pretty good, but for the cut-off kickstarter shaft! Searching eBay auctions was helpful in finding a “1967” transmission that looks pretty good for $75 delivered. I hope that it has a good k/s shaft in the whole package. There were mild amounts of grit/gunk on the bottom case half, consistent with low run time. The pistons did have a decent coating of oil burned onto the crowns, so it did run for awhile and fortunately there were no signs of piston seizures. My concerns about the lack of a stop for the kickstarter shaft turned out to be moot as the whole kickstarter pawl/spring/plunger had been omitted during assembly. The oil pump is a replacement CL77 assembly, which was the superseded part for the Dream/Super Hawk pumps.
A second day of work and inspection revealed that the cylinder head had been ported and 1.5mm o/s intake valves installed in newly cut seats. There was a coating of carbon/varnish on the back sides of the valves, so the next step was to remove the valves, after taking out the rocker pins. The 350 kit and/or the camshaft kit came with some S&W (probably) valve springs, alloy retainers and cupped valve spring seats to protect the alloy head. Some kind of hardening gasket glue was used to double-gasket the cylinder head cover, which took about a half hour of spraying paint stripper and use of a hammer and gasket scraper to get all the remnants off the mating surfaces. Cleaning parts is not one of my favorite pastimes, but you don’t want to reassemble a motor with uneven metal surfaces and gritty bits of gasket material leftover on mating surfaces.
Having given or tossed out many old engine crankcase halves in the past six months, the one piece I retained was a bottom case half, but it had been steam blasted to get all the grease and varnish off then abandoned in a raw aluminum state which then became all fuzzy and scaly from moisture exposure. I recently met a young man who was doing fine, artistic restorations of CB160s and other small Hondas. He purchased a “parts bike” CB77 from me and left his card as we parted. He said he has a dedicated blast cabinet for soda blasting which is just what this crankcase half needs right now. I dropped off the parts with him the other day and am waiting for their return, along with the delayed shipment of the transmission.
I’m still mulling it over now…. Rebuild the hot-rod engine or put it back to stock and sell the racing parts separately. It is a tough decision…
Bill “MrHonda” Silver