Motorcycle Repair: engine noise

Question
QUESTION: hi,
I recently bought a honda c77.
pistons etc. are okay.
also the cam chain seems okay.
after the first strart the engine makes a very strange constant noise
as well as a circular saw. screeming very loud
I did not split the crankcasses,
but cleaned the filters.
if i use the starter motor is also the kick starter down.
that I can just stop.
have you any idea where I should look for or what this could be?
this before I took out and and open the complete engine.
engine no C77E 1,003,322 (1962 ??)
thanks
Sam
The Netherlands (Europe)

ANSWER: Sam, if the screeching sounds are coming from the right hand side of the engine, it is probably due to the starter clutch rollers/springs/hub needing attention.  

You need a 16 x 1.0mm bolt or use an aftermarket rotor pulling tool of the same size to remove the rotor from the end of the crankshaft. You can do this through the dyno cover w/o pulling the whole kickstarter cover. HOWEVER, if the kickstarter arm is DOWN and not returning, either the cover wasn't installed correctly (not winding the spring properly) or the kickstarter connection knuckle is split down the side and the knuckle is jumping over the spines on the end of the kickstarter shaft.

The manual kickstarter and electric starters are really two separate systems, so one can work if the other doesn't.

There can also be other issues with a worn low-gear bushing in the transmission and/or the kickstarter pawl/spring/plunger parts worn out/slipping. Either one of those requires engine removal and splitting the cases to service the bottom end.

If it has a lot of miles/kms on it, the best thing to do is to tear it all down and replace whatever is necessary.

Your serial number shows an early 1965 production number. They began with 7 digit serial numbers in 1965.

I offer a full restoration guide package available on CD or download for all versions of the 250-305 Dreams. See my website for details.

Bill Silver
www.vintagehonda.com


---------- FOLLOW-UP ----------

QUESTION: Thanks Bill,
The noise came from the starter clutch (one of the screws was loose)
It looks like a newer engine is placed because the papers indicate that the Original engine and frame numbers are:
Engine: C77E-111776
Frame: C77-11766
papers said that this bike was on the road 1th of March 1962.
Thanks a lot.
Sam

Answer
Sam, the 1961 engines had a breather system in the back of top crankcase and did not have a tensioner for the primary chain. The 1965 engine would have a few upgrades that make them a little more reliable.

A 1961 bike sold and on the road in early 1962 all makes sense to me. Honda used a 5 digit serial number starting with a 1 in 1961, a six digit serial number starting with a 1 in 1964 and then the seven digit number starting with a 1 in 1965.

Enjoy the project.

Bill Silver