Engine/Clutch severe vibration at WOT - NOT

[John Miller]

I have had this issue for several months, thinking that it was clutch basket bearings or wear that was causing a severe vibration (like out of balance or run out) but only when under severe load like WOT from 3,000 RPM upwards.

I have been really concerned thinking I was going to start pulling her down starting with the clutch.

Whilst I bought the bike from an aircraft mechanic who had fitted the crash bars all seemed to be professionally done with appropriate hardware and self locking nuts I never thought I needed to double check bolt torque etc.

Was surprised to find the front engine mounting bolt was at least 11/2 turns from tight.

Now I believe I have found the issue - nothing at all to do with the engine vibration or clutch basket wear - just a loose front engine mount bolt causing the severe vibration under heavy load.

I will source a new bolt to replace the original - assume it will be over stressed after the hammering it's been getting.

Moral of the story is take noting for granted, check all the obvious things first.

 

[idk]

Tighten it up and you should be okay.

However, if you do want to replace it, use a jack to take the weight of the engine and the old bolt will easily slide out and the new one will easily slide in.

 

[Kevin frazier]

Yes take nothing for granted especially at like you say under severe load at WOT (me like hehe)