Isolastics help

I am confused. There seem to be a lot of different types of isolastics out there. Here is a picture of what came out of my 69 S.



The PTFE washers were completely disintegrated. The shims are not in the picture. On the front iso, the two small rubbers were completely loose on the spacer and on the rear, they are rather loose too. When I look in the spares list, I see several parts I do not have. On page 8, I do not have B5 06.0772 (2) and B16 06.0771 (1), the front and rear engine mounting seating spacer. Do I need these parts with replacement of original parts? My other option is to order the Norvil replacement isolastics from the UK, or are they available here in the US? I understand that I have the option too of using the Hemmings adjusters, I would still have to get parts, or upgrading to the MK3 system, but that would involve some machine work on the front mount plus parts. The parts for the original system is around $130, and the Norvil replacements are about $70 each, so it is a toss up as far as price. I guess the Norvil Isos will look different on the bike?

Also in the Haynes manual, it doesn't show the engine mounting seating spacer, nor does the commando workshop manual, but that one is real hard to read, it is an assembled cutaway drawing. The Haynes book shows circlips on the spacer tubes I guess to keep the small rubbers in place. I also assume this was an improvement from the 69 bike.I found the Mike Randell page on isolastics and that too was quite confusing to me.

Any help would be appreciated.

Thanks,
Dave

Dave, I recommend fitting a pair of new Norvil isolastics. They are easy to fit and keep in adjustment and they also move the vibration point to a different place in the rev range, thus smoothing out the running at a less obtrusive point. The Norvil ones are a bit more expensive, but this should be compensated for by not having to machine the front mount to accept the longer front isolastic from other suppliers - the mount is tough material and quite difficult to machine. You can also order the PTFE washers and rubber gaiters, which are different on the earlier style isolastics.

Hello all, I to have worked my way to the motor mount s on my 75 mk111 commando . Let me see if i got this right on checking and setting my clearances on a Old Britt headsteady they like minimum gap .001' same with front and rear motor mounts(Isolastics) .001" Service manual recommends .005" to .006" any one experimented with these clearances? Thanks M.C.

Trouble is setting it at .005 may lead to a .010 gap somewhere else because the tubes were not square to start. You could end up with .005 in one spot and .001 in another and that would make it shake indeed. Long ago we make a fixture to true up the ends of the weldment tube so that true readings will repeat. Than .005 works good for most.