Vernier Isolastics

Hi Fred I think you will find that that's the adjustment side and should be slightly loose. What happens when you tighten the through bolt ?

You should tighten the Verniers until finger tight against the engine mount and then loosen the adjuster side by one and a half HOLES (not turns). This will give enough clearance to allow the internal rubbers to float in the mount and tightening the through bolt will merely hold the Vernier end caps in place, leaving room for the rubbers to float in the mount and reduce overall vibration. It's not a great system but better than the old shim it every weekend idea!

Previously fred_goode wrote:

Thanks Hans. This is with the mounting bolt torqued to 30ft/lbs. I was wondering if the unmoving end cap could be transmitting vibrations to the frame by bridging the Isolastic gap

I Don't think so Fred, because the end caps stay still next to the frame, then the ptfe washers allow the movement, which is only up and down, that's why the gap is adjusted to less than 10 thou .

fwiw,

I have a Mk3 and I have never been able to adjust the isolastics to give a satisfactory result by using the 'correct' method.

I find that, after checking/setting the clearance by turning the screw adjuster, all clearance disappears when the through-bolt is tightened. The result being lots of vibration.

I start by using the 'correct' method, then road-test. Then I increase the clearance in stages until the vibration period drops to 2500-3000 rpm whilst riding. It works for me and the situation could be due to iso's which have not been changed during my ownership.

However, the fact that tightening the through-bolt takes-up the clearance that has been carefully set beforehand would surely happen with new rubbers, would it not?

I had "vernier" (actually no such thing) isolastics on my Mk 1 850 and I found the best method of setting them was to ignore the holes and use feeler gauges as on the earlier style. Around .010" front and rear seemed to suit my bike.