You are here:

Motorcycle Repair/Honda 350 cam question follow-up

Advertisement


Question
Hi, Bill. This is a follow-up to a question I asked a while back about a loud vibrating noise to my CL350 ('71 motor). Finally got some time to yank the engine and discovered that the "rebuilt engine" (which really did look rebuilt with new gaskets and no carbon on the valves or piston tops) had either a stretched or overly long cam chain that was slack enough it had been slapping against the walls of the head. Seemed to be a couple links too long (I don't know for sure because after removal, a dumpster diver promptly stole it from the carport where I had laid it aside), and I assume that was causing my rumble/vibrating sound. OK, so we ground it apart, wired on an open Tsubaki, pulled it through the engine, and prepared to link it together as a replacement chain.

Sounds simple, right?  Well...we did that and discovered that the Tsubaki is a link or two too short! If we force it up into position for linking, the chain is so tight that the tensioner will not retreat back into the case. So I shook my head, concluded there is some problem with the Tsusbaki, and ordered a stock 94 link cam chain. Chain gets here and I repeat the process with the same results: While everything I can find indicates this bike (and all cb/cl 350s) takes a 94 link cam chain, a 94 link chain comes up at least one link--and maybe two links--short. It's easy enough to add another link or two, but any idea why I am running into this problem? I don't think the chain is hanging up on anything, and we're rotating everything to account for slack, but we're coming up short no matter what we do

Answer
Vince,

Yes, all the 350/750 and even the 250-305s use a 94 link camchain. I worked on a 350 last year and faced some of the camchain install challenges you mention. Certainly, getting the guide roller setup to stay down in the case, with the two damper pieces was especially challenging.

As long as you know that there is no interference along the camchain run from the crankshaft, the factors that will affect the "short chain" effect are the stack height of the cylinder, cylinder head and the gaskets between them all. Make sure that the new gaskets are the same thickness as the old ones. I have seen some variations in aftermarket parts. Leave installing the camchain tensioner to the last step, once the chain is attached.

The other thing to do to mitigate the new gasket issues is to put a socket/spacer over the ends of the cylinder studs and gently torque them down, to compress the total height of the top end components. You just need a couple on the top and bottom to help bring the height down to where the camchain can be re-strung on the sprockets.

Bill Silver  

Motorcycle Repair

All Answers


Answers by Expert:


Ask Experts

Volunteer


Bill Silver

Expertise

Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.

Experience

I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

Organizations
VJMC (Vintage Japanese Motorcycle Club) of North America

Publications
VJMC newsletter, as editor for two years and as contributing editor currently.

Education/Credentials
3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

©2016 About.com. All rights reserved.