Checking front Cam Chain Guide thru sump?

Ive been meaning to do this job now for a while but just dont have the confidence built up ,Yet!
I guess whats holding me back is weather the guide is original or not and if its intact or
possibly separating . I can hear a light knocking on cold start that goes away after a 10 minute ride.
I vaguely recall the original owner state that he changed the guide when he had the motor apart
for rings ect but im not positive. He was an old Yamy mechanic for many years and got the bike because of the low miles on motor. But bike obviously sat for a long time so he was doing the full on frame up restoration but ran outta gas I guess. It was 90% finished when I got it. Regardless I was wondering based
on a post I read that if u remove the sump there s enough to room to slip a thin probe up and see if the guide is still intact before getting into the job. Whats the worst case if the guide completely separates .
With all the talk on this being a common wear item im sure some have experienced what the outcome can be if left alone. Thx for any guidance .

An old Yamaha mechanic doing a frame up resto would almost certainly have replaced the guide. Pull the sump and look for black bits of hard rubber. That's the first sign of a guide coming apart.

Hey Jim,Thx for feedback. I will check that. Anyone know if u can scope thru to the inner engine were front guide
is located.

I don't think you can scope up from the bottom. Here's a pic with the sump plate removed and there appears to be a casting in the way .....

Thx 5T . Dosent look like its doable. I though I read somewhere there was a small gap but I cant find the info now.

Post a video on what it does and have experts watch and comment.

XS650D said:

Ive been meaning to do this job now for a while but just dont have the confidence built up ,Yet!
I guess whats holding me back is weather the guide is original or not and if its intact or
possibly separating . I can hear a light knocking on cold start that goes away after a 10 minute ride.
I vaguely recall the original owner state that he changed the guide when he had the motor apart
for rings ect but im not positive. He was an old Yamy mechanic for many years and got the bike because of the low miles on motor. But bike obviously sat for a long time so he was doing the full on frame up restoration but ran outta gas I guess. It was 90% finished when I got it. Regardless I was wondering based
on a post I read that if u remove the sump there s enough to room to slip a thin probe up and see if the guide is still intact before getting into the job. Whats the worst case if the guide completely separates .
With all the talk on this being a common wear item im sure some have experienced what the outcome can be if left alone. Thx for any guidance .

Click to expand...

May be you've already done it, but before pulling the sump plate, check the valve lash and cam chain tensioner for proper adjustment.

Yes ,all done and tuned to perfection .Its something else going on. I did notice that pulling the oil filter had an immediately reduced
almost silenced the knocking sound from the front lower end ive had for last few years. I tried running the motor with a clean oil change I had just done (no filter)
figured it would be fine for a short run. Yes I change the oil regularly with Dino 20/50(not oil related) but it could be bad guide as I think 5T had
mentioned last season, the front guide is starting the separate and u will hear the chain hitting against the guide possibly with a cold motor until the oil
splatters up onto the guide enough that the sound stops. This is a big job for me ,no engine lift and limited skill and tools to do the job.
A lot of work just to look at the guide that may or may not be ok. Had a few quotes from local shops but were talking $2000 CDN by the time its all
done with parts . Im not working rite now with this Virus.I certainly have the Time. Why is it when u have the time u dont have the money and when u have the money u dont have the time Lol

XS650D said:

Ive been meaning to do this job now for a while but just dont have the confidence built up ,Yet!
I guess whats holding me back is weather the guide is original or not and if its intact or
possibly separating . I can hear a light knocking on cold start that goes away after a 10 minute ride.
I vaguely recall the original owner state that he changed the guide when he had the motor apart
for rings ect but im not positive. He was an old Yamy mechanic for many years and got the bike because of the low miles on motor. But bike obviously sat for a long time so he was doing the full on frame up restoration but ran outta gas I guess. It was 90% finished when I got it. Regardless I was wondering based
on a post I read that if u remove the sump there s enough to room to slip a thin probe up and see if the guide is still intact before getting into the job. Whats the worst case if the guide completely separates .
With all the talk on this being a common wear item im sure some have experienced what the outcome can be if left alone. Thx for any guidance .

Click to expand...

if you read there's a small opening to get a scope through, next time you change the oil lay it gently on it's side and carefully look for one.

i think the rubber was off my guide for quite a while. the metal had a good gash cut into it by the chain. i had the engine apart due to a different problem, or i'd never have known about it. so i replaced the guide, and i couldn't tell you if the new one immediately separated or not

i guess the only symptom was a very slight whine that could have been anything if you even ever noticed it. i did notice if you straddled the bike and tilted it and listened carefully the whine would change, maybe as gravity made the chain hit the side of the guide. mine might have been off 10s of thousands of miles. no huge effect that i know of...