1975 Norton 850 Restore

MS850 said:

L.A.B. said:

MS850 said:

Also seems to vibrate more than what i remember on my '70 Commando. It smooths nicely above 4K, between 2.5K-4K get tingling at the grips.

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Try backing off the Isolastics by 1-2 holes, and also slacken the head steady suspension spring nut by a couple of turns?

Edit: I don't remember you mentioning whether you changed the Iso. rubbers or not-so it could be they are in need of replacement if increasing the clearance doesn't reduce the vibration?

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Yes I did replace both Iso's, Im not sure they are adjusted correctly. I have clearance .008 on the side with the adjustment but none on the opposite side.
thanks

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L.A.B. said:

None of the info relating to the MkIII type kits seems to specify setting the clearance with a feeler gauge, but if you wish to do so then I suppose using a version of the earlier adjustment procedure will do.

I would try this:
First, the weight of the bike should be supported by the lower frame rails using a jack, blocks of wood or similar, so that the main stand is not touching the floor if it is a later model that has the main stand fitted to the cradle.

Checking front Iso. unit:

Slacken the central Isolastic bolt locking nut, pull the inner part if the L/H Iso. gaiter away from the Iso unit, lever the engine towards the right side and hold it there.
Then insert the feelers to measure between parts [23] and [24] on the left hand side (as shown on the parts book drawing link below)

http://www.bsa-regal.co.uk/norton/parts ... &Plate=015

The front Iso adjuster should be on the right hand side of the front Isolastic unit.

Check/adjust Iso. clearance then re-tighten the Isolastic bolt/nut.

Check rear Iso.

Slacken either Iso. stud nut. Push the rear wheel to the left and hold it there whilst checking, use the same procedure as for the front Iso. but this time check clearance on the right-hand side, the adjuster being on the left side of the rear Iso.

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Update

Backing off the *original* MkIII Iso. unit adjusters by a fifth of a turn sets the correct clearance, however the *conversion kit* adjuster setting could be different?
The Norvil recommendation for their own kit is back off the adjuster by half a turn. http://www.norvilmotorcycle.co.uk/techtalk04.htm

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Torontonian said:

Keep that seat away from sunshine. Park in shade . Or indoors if possible. People worry about rain but it's sun. Pleats fail faster than unstitched too. So take care of it. No fat chicks.

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