hey guys,
 I have a problem with engine vibration and was wondering if anyone could
help me to reduce it...

problem is when at idle all is ok all the way up till 4100rpm than a really
bad vibration is heard and felt through the fairing and frame than it goes
away at about 5500rpm to the normal big bore engine vibes...???

i have tightened the frame bolts and all the fairing mounts. i have
syncronised the carbies. but i have not done the valve shims yet.

anyone have any ideas please...