Honda C77 rebuild parts 1-3

Classic Motorcycle Mechanics > Japanese > Workshops

By Richard Rosenthal > Originally published June 2006

Honda C77 motorcycle restoration (pdf)

Ignoring his own advice, Richard Rosenthal buys a totally dismantled, probably incomplete Honda C77 in an effort to live out a teenage dream. Here he sorts the kit

Although an unknown face to many Mechanics readers, I've been involved with classic motorcycle journalism for 15 years, much of it with sister magazine Classic MotorCycle. My favourite column, You Were Asking', allows me be an agony aunt-cum researcher and, although I've restoration experience and an extensive library, I'm lucky to work for a great readership who always help out when I can't.

For four decades I've been a classic bike fan, buying my first vintage machine, a 1924 550cc OEC Blackburne, in 1971. Almost 35 years later it's still going strong and I love it to bits, but... it's gained many playmates, including a 1934 New Imperial, 1957 NSU Max, 1962-9 Racing Kreidler, 1911 Premier, 1963 Exc... DKW... 1918 New... Got the picture? Sad, maybe, but it's a great way of life.

Over the years I've run a handful of Japanese bikes, including a few Hondas and a Yamaha XS650, but I've never restored one so it's about time I did. Not one to relive my past, many of the times and bikes were brilliant, as are the memories. And as memories is how I want to leave them. But to sample what I've never had, now that's a different thing altogether. As a cash-strapped teenager in the mid-1960s I lusted first after a Honda CB92 Benly 125cc twin, then the C77 and CB77 305cc twins parked near our rented caravan on a Felixstowe holiday site one summer. Other favourites included a BSA 441cc Victor (magic engine capacity, eh, or so I thought), Suzuki Super Six, Suzuki Stinger and a Yamaha YL-1. An odd selection, but teenagers were odd animals in the 1960s. And with good reason.

Leap forward to 2005. Son Peter, a trader of classic British and European parts and motorcycles, parks on the drive with a pile of dismantled blue junk in his car.

"What's that?" I enthuse

"It was Graham's... he wanted it gone," growls Pete.

"It's a C77," I enthuse, trying again.

"£200 and it's yours." "Done."

"You were," grins Peter, now enthusing and pocketing the bundle.

The aim
While I enjoy shows and concours events, riding is my bag both in the UK and abroad. Our classics cover fair mileages in all weathers except the depths of winter and many have been tied on ferries, ridden along byways and overloaded with luggage. The C77 will suffer the same fate. With this in mind the aim of this rebuild is a smart machine using as many original Honda parts as possible for a modest cost, hopefully around the £1500-mark.

However, to complete the teenage dream, the twin will be refinished in deep black enamel, just as I remember the motorcycle I coveted in the summer of 65, and it will sport a pair of slim megaphones. But purists needn't fret, I'll keep the originals just in case I grow up one day.

Click on the download link to view the first part.

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View original Honda article (pdf)

MODEL HISTORY
Honda's design philosophy right from the outset was that small, multiple cylinder engines could produce more power and run more smoothly than big singles. The 247cc C70 Dream, launched in September 1957, borrowed from the NSU Rennmax design and was the first real attempt at a 250 performance four-stroke twin for the masses. The dry-sump SOHC engine ran a pressed-up ball bearing crankshaft with horizontally split cases and a chain driven camshaft, and developed 18bhp. In 1959 the C70 became the C71 with an electric starter, and the first 305cc version appeared as the CA76, made for the US market.

For the 1961 season, Honda revised the engine to a wet-sump design, deleting the oil tank, and offered the Dream in both 247cc (C72) and 305cc (C77) versions. Both bikes continued with the pressed-steel frame, leading link forks and 16in wheels of the earlier bikes, and it was the CB72 and CB77 designs that pushed the engines to new levels of performance with their single-loop, tubular steel frames, telescopic forks and 18in wheels.

The C77 retained a 360 degree crank throw (as opposed to the revised 180 degree crank on the CB version), and Honda quoted a power output of 24bhp at 8000rpm, with a dry weight of 143kg. With a top speed of almost 100mph, the bike continued in production more or less unchanged until 1969, when it was replaced in the showrooms by the fast and stylish CB350. Our bike dates from 1966 and represents a typical example of the pressed steel Honda 305 Dream.