80-84 Liquifire engine vibrations

[mr-spock]

I Recently got my 82 liquifire running and its running verry good. But it has a lot of mid rpm vibration I wassnt shure how much is normal for these sleds. I have noted that the motor mounts dont allow much movement compared to the other sleds ive ridden. So whats you guys experiences with this?

[harleysportster]

Try to determine if it is track, driveline or engine.

[mr-spock]

Its defanatly the engine because it changes with rpms. Could it possibly be the clutch? It had a commet 108c on it when i got it and it looks as if it didn't fit correctly so the previous owner took a grinder to the back side of it. And made a groove so it would clear the motor mount bolts

[ljm]

I would think that could do it. Would be interesting to switch clutches.

[rminier]

TOSS that clutch!! They are extremely sensitive to proper balance. When you work on a clutch, you have to make sure that you put it back together with the arrows on the parts all lined up to maintain balance. When you wrote that someone ground on the back of it to prevent it from rubbing?? !!!
It is possible that if this vibration is definitely restricted to the engine/clutch area (not the drive line) you MIGHT have a problem with the crankshaft or something else in the engine.
But, the first thing I would do is find another clutch, even temporarily from another sled and see how it acts.

[That Girl Racing]

Pull the clutch off, rotate it 180 degrees and reinstall it. If the vibration doesn't change it is probably the clutch. If it changes for better or worse I, it is probably a crank issue. That is how I start to figure out vibrations.

[AirborneX4Special]

My 82 had a vibration I could feel through the handlebars that worsened as rpms increased. Switched clutches and it made no difference, turned out to be a bad crankshaft.