Hey gang!

I'm new to the forum, new to atv mechanics currently "rebuilding" an old moto4 thats been in the family for about 20 years. I got it running after a carb rebuild but the engine sounds.. clunky hehe
I did have some metal shavings in the oil, mostly dust flakes in the oil filter but saw what looked like copper flakes also, which makes me fear i'm having bearing issues. Compression is abit on the high side (+5psi of max allowed) but it does look carbonated..

I made a quick video, quality is crappy but it gives an idea of what it sounds like;


Let me know if you got some imput !!

Thanks!

 

Sounds like you need a new cam chain.

 

I will try to get a look without removing the engine to see how it looks,

I'll also make a video from cold to warm this afternoon with better quality..

 

Timing chain seemed tight with no apparent damage to cam sprocket teeth, will continue to investigate!

 

Did you ever find the problem? I just bought one today and got it started and it's making the same noise

 

Doubt if you will get an answer to a 4 year old post. The OP didn't follow up then. The video sounded like cam or followers completely shot, but cam chain or valve seat loose are other possibilities. The best thing to do is take the top end apart, checking and measuring everything, and fitting new parts if the old ones are worn beyond specifications, which you will find in the workshop manual.

 

I have the same issue.
was wondering if you figured it out.