Ennoying vibrating noise

[Jgb19830]

OK guys I've always had a buzzing /vibrating noise coming from the front of the engine / exhaust area when I come off the throttle or a low rpm. This only happens when ridding not on idle. I've checked for anything obvious as nothing loose. I've read somewhere that the power valve could be the issue any idea what I need to check for as it has just been machined to match the rebore by pmje

[Calum]

You didn't fettle with the bottom end did you?

The clutch has to be balanced, and the engine has to be timed up with the balancer shaft.

Otherwise, it's a two stroke...it vibrates.

[declan]

@Calum is it just normal vibration or does it cause issues if it’s not all balanced

[Jgb19830]

Turns out to be access movement in the power valve bushes so need to replace these

[declan]

@Jgb19830 let me know how you get on

[Calum]

Yes, this was mentioned in a previous post.

On a TDR250 worn powervalve bushes caused the engine to seize!

So yes be careful with that!

[Jgb19830]

I have pinned it open for now to see if this is the cause of the problem

[declan]

@Jgb19830 I doubt that will make a difference but who knows

[Jgb19830]

OK so it's not the power valve making the noise... Has anyone ever had a noise coming from the small end bearing? If so any videos of the noise?