Mk III Isolastic assembly procedure help need!

I've just acquired the vernier isolastic assemblies for the front and rear engine mounts as supplied for the Mk III 850's. I've looked/searched with no success on which end goes on the left or right, etc. One of the thread on ends has a set screw and on the exploded diagram I can make out that this goes to the left (as when setting on the bike) on the front mount but not much success with rear. Also the rear tube with the rubbers mounted is not threaded the same way on both ends. One end has thread to the end and the other has approximately 1/2" of some surface before the threads begin. Also....what the heck??? are the little clamps for?? They look like constant-velocity boot clamps and I can't figure out what they accomplish. Thanks for any help and sorry if I'v reopened an old thread but I had no luck with a search of the forum.

Also....any idea of where a free downloadable service manual for the Mk III Commando 850 might be? One of the diagrams from the MkIII exploded parts catalog was included with the vernier purchase but not enough detail or explanation for me to assemble it.

www.oldbritts.com has all the illustrations where you can clearly see the order of assembly.

The clamps are basically useless IMO... The cap with the set screw goes on the end that's not threaded all the way with the flat. As for which way you mount them I don't think it matters much as long as the front and rear are opposites.

Thanks for the response. The diagram on Old Britts is a lot clearer than what I have seen.

Another question on isolastics upgrade...........Will the front and rear mount endcaps from the '73 installation replace those from the '75 Mk III installation? I see they are different part numbers and the total cost is close to $50-60 so if I can use the old ones I will. By the way, thanks for the tip on using soapy water to install the rubber isolastics in the mounting tubes!!!

I have been told that older bikes need a modification to the front engine mount (boring?) in order to use the Mk111 Isos. What's the scoop on that?
Thanx.

grandpaul said:

http://www.oldbritts.com has all the illustrations where you can clearly see the order of assembly.

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Good reference but you'll still need a parts book (Old Britts photos taken from parts book) with part numbers and a manual. If you can afford a money pit like a Commando I'm sure you can afford $60 for a parts book and a manual.

Thanks Coco.....I've got the parts manual and service manual for the '73 850 but not the '75 with vernier isolastics and I'm a little reticent to pop $ for a manual which doesn't fit my bike except for the motor mount system. I tell most people that the reason I've got money to spend now is that I didn't spend it frivously on things in the past but you have a good point about having bucks to have a Commando so I'm not going to let the price of a service manual for a electric start 850 stand in my way too much. If I need to get one I guess I will but I'm hoping to find the information without having to get the whole manual.

In reference to the previous poster and the need for modification of the front engine mount tube.....I'm fortunate in that I have a buddy with a pretty complete machine shop (Bridgeport mill and large lathe) but I still figured it money ahead to buy a front engine mount already machined. The only dimensions I've been exposed to are that the tube on the front mount needs to be machined back to 5.5 to 6.0 mm out from the flange on both sides. I haven't seen this in stone and proceed at own risk. Maybe it's common knowledge but I don't find common knowledge all that common. Most of it's new to me and that's why this forum had been a godsend to me. Thanks to all.

I can confirm the mod to the front iso mount is to face off 5/6mm from one side to even out both sides. Easy on a lathe.

Diamondjet said:

Thanks Coco.....I've got the parts manual and service manual for the '73 850 but not the '75 with vernier isolastics and I'm a little reticent to pop $ for a manual which doesn't fit my bike except for the motor mount system.

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Got it. I didn't realize you need one just for the isos. I am sure someone can supply the info. If I had a scanner I'd scan the pages for you.

YOU DON'T NEED A MANUAL. THERE ARE MORE THAN ONE GOOD THREADS ON INSTALLING NEW ISOS RIGHT HERE ON THE FORUM!

Sorry for the ALL CAPS, too lazy to re-type it.

Diamondjet said:

Another question on isolastics upgrade...........Will the front and rear mount endcaps from the '73 installation replace those from the '75 Mk III installation?

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Yes. I reused the ones from my 74

By the way, thanks for the tip on using soapy water to install the rubber isolastics in the mounting tubes!!!

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The recommended lube is SylGlide (sp) or similar silicone based grease. Water seems like a bad idea, since I've seen many photos here of rusted iso stuff.

And the recommended position of end caps is the adjustable side on the right for the front and on the left for the rears.