Most of the vibration was caused by out of round wheels.
After trueing the wheels, I had a look at engine mounts and the head steady.
One of the engine mount bolts was loose and another was misaligned . A bit of work with a die grinder fixed the misalignment.
That reduced vibes again.
Then I had a good look at the tank and seat mountings. The metal seat pan was contacting the frame. New rubbers fixed that.
The tank was bolted up with regular bolts and pieces of 1/4 rubber between tank mounts and tank. This is essentially solid mounting.
I found that the two front tank bolts, although not illustrated on the very poor Domi parts diagram, had 2 different part numbers. This made me think that the regular bolts in the tank were wrong.
I gave the part numbers to Mike Partridge at Walridge and, although he wasn't familiar with the bolts, he could order them and the proper tank rubbers.
He was surprised at the cost of the bolts, $16 and $12.
I was happy to hear that they were pricey as it seemed they might be special, and of course they are. They are shoulder bolts, the left side longer to mount the regulator heat sink, ( or was it the horn?)
Anyway , this arrangement clamps the tank to the rubber just like the Vincent tank mounts, only turned 90 degrees.
This helped to furthet reduce vibration as the tank is now isolated.
I still get some vibes through the footpegs at around 4 k rpm, might try isolating them.
Or perhaps do the dynamic crank balance as Martyn did.
Anyway, it is decently smooth now.
It would be good to ride a dynamically balanced 650ss to see if there is more improvement to be had there.
Glen
