hi i belive i have an engine vibration at 100km/h, at 110 its gone and 90 its gone. it to do with eng speed as u pull the cluch in and let the throttle go and its gone , is this a common prob, normal for a k100rs 1986 ?? while the bikes off the road and i am doing the diff i thought why not get stuck in to it,

Hi Alex, there are quite a lot of reports about vibration on these models and it is obvious they are aimed at the European markets with higher speed limits as the vibration cuts in just as you mentioned.

On mine it is noticeable from about 3700 onwards and then disappears at somewhere over 4200. Mine being an earlier model than yours will be more noticeable but I don't find it intrusive so has a fairly "typical" 4 cylinder vibration.

The 4 cylinder models don't have a balance shaft unlike the 750 which is apparently smoother.

Regards,

Phil

Have a look at your alternator bobbins, heard before that if they're hardened or wasted you can get extra vibs at that ref. Cheers, Rene.

thanks guys. i have a rattle at idol near the alti so ill have a look.
cheers. and yeah dose feel like harmonic engine vibation