Front isolastics

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Nortoncommandoneil

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Hello, I have a Norton Commando Roadster mk2a 850 1975 that is fitted with shimmed front isolastics that i want to change to vernier type. What is the difference between MK2A and MK3 from a visual point, so that i can order the correct replacement parts.

Looking at my set up it appears that the bolt that passes through the middle of the isolastic rubbers and through the triangular plates attached to the frame seem to be equal at both sides.

Thanks for any help with this. Also any pics would be a great help.

Neil
 
You need to buy the Vernier setup to suit the front mount tube that surrounds the iso rubbers, pre mk3 this has unequal sides, MK3 has equal sides and there are now Vernier setups to suit both. Previously you turned the long side to be equal to the short side and fitted the MK3 Vernier setup.
 
Thanks for the reply about my isolastics.
I take it I have the MK3 Front Engine Mount because looking from the front of the bike both sides seem equal that pass through the lower frame plates
 
Nortoncommandoneil said:
Equal sides and original shim set up and it’s pre- MK3.
Click to expand...

On a pre-Mk3, both 06.0422 front 'collars' are the same part so are "equal".
The lengths of mounting tube that extend beyond the mounting plates are not equal (because the engine/cradle assembly is offset left of the frame centre line).
 
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Is there Much advantage between the original set up with shims and the cheaper none vernier item.
Also is the full stainless version worth the extra cost. I’m also fitting a D Taylor head steady.
 
Nortoncommandoneil said:
Is there Much advantage between the original set up with shims and the cheaper none vernier item.
Click to expand...

Which "non-vernier" item?
Both kits mentioned above are vernier.

050484
"VERNIER FRONT ISOLASTIC CONVERSION KIT TO FIT PRE MK3 MOUNT"

050484C
"VERNIER PRE MK3 FRONT ISOLASTIC CONVERSION KIT, FULL (WITH END CAPS AND PTFE'S)"

The original shimmed assembly is non-vernier.

Nortoncommandoneil said:
Also is the full stainless version worth the extra cost.
Click to expand...

That depends whether the existing end caps (and PTFE washers) are reusable or not (or if you want to reuse them?).
 
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I did my MK2 850 front iso to vernier pre-MK3 using the kit from Norvil. This was the lower cost setup without rubber boots, washers etc. I reused original washers and ordered fresh boots separately. I was expecting to need to remove header pipe to withdraw the main through bolt based on Mi Ty's video of his MK2A's replacement ...but my bike had the bolt head on the left side, nut on the right so bolt can be removed full out to the left....timing case blocks the right side.
Though red Rubber Grease is often recommended for lubing new rubbers as they are inserted, that product is hard to find around here, I just used dielectric grease, which is non petroleum silicone based and rubber safe. Worked fine.

Also, when refitting iso bracket back on bike, I needed the use a block of 2x4 wood to pound between the frame downtubes to wedge them apart just a scoish to enable fitment.
Otherwise, all went well.
 
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