vibration around 3000 rpm

Just got back from a 200 mile ride today and the Commando ran great. Installed a new set of vernier adjustable isolastics last year and still don't seem to have them adjusted quite right. Getting vibration around 3000 rpm, not below and not above. Does this mean that the rear iso is still too tight? Any advice greatly appreciated!!

Could be any of the the three if too tight. If the original crappy top one is there, that won't make it vibrate, just give you lousy handling. The other two can be for sure too tight, just have to check for up down movement (lever between the motor and the bottom frame gently...and feel for a bit of movement at the iso shims) Play with them till it is just a bit of freedom and you will get less vibration and the best handling. It's a feelie touchie thing but you will get it after a few tries. By coincidence, I had to do my front one yesterday,it had started to rattle when I goosed the throttle, and I over tightened it....awful vibes at over three grand last night...so it's now Sunday morning, and that is on the list of most important chores...as you see...even someone who has had the pleasure of verniers for a few years, takes a couple of tries to get those adjusted right...but it will be worth it...great modification and top on my list of the ones I would do again on any future Machine.
:wink:

Thanks Hewho. I will start from scratch resetting both again. Did I read somewhere that a half turn out is about 0.010? Yes, I still have the original headsteady and plan to replace that at some point with the Taylor? or the Old Britts. Is one preferred over the other? I think there were a few threads on this a while back I need to check.

tpeever said:

Did I read somewhere that a half turn out is about 0.010?

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Possibly the conversion kit adjuster threads are different?

But 1/5 (one fifth) of a turn (or turning by 1.5 holes) is equal to 0.005"-0.006" on the original 850 MkIII vernier adjuster.

I read a comment from a Forum member about measuring the isolastic clearances with a feeler gauge even when you have vernier adjusters. This was a good tip for me. I found that when I turned the adjuster by the required amount and then tightened the engine bolt, the clearance would reduce substantially due to slack in the threads. I now set them to 10 thou by first making the clearance between the adjuster and the PTFE washer larger than 10 thou, then tightening the engine bolt, then measuring the clearance again. You might need a few tries until you get it right, but my bike begins to smooth out at 2500 rpm and is smooth by 3000 rpm. You might try this on yours, tpeever.