for your info

Joined
Oct 28, 2014
Messages
952
Country flag
I replaced the front iso in a 1974 850. Installed the new adjustable type. From start too finish ...and adjusted was 4.5 hours. So now you know how much time to allow for the job. I made a special tool so I could use a cordless drill to draw out the rubber stuff and insert the new piece, and made line-up bars to install the iso back into the bike. What took the longest time was to R&R the isolastic holder, it's like a Chinese ring puzzle.
 

Craig

VIP MEMBER
Joined
Dec 20, 2005
Messages
2,376
Country flag
Speaking of ring puzzles , the rear brake lever safety spring is a head scratcher for a couple of whiles , too ....
 

TomU

1972 Roadster
VIP MEMBER
Joined
Sep 22, 2015
Messages
133
Country flag
Was 4.5 hours just for the front :eek:
 

L.A.B.

Moderator
VIP MEMBER
Joined
Nov 20, 2004
Messages
15,815
Country flag
Having replaced my Mk.3's front and rear Iso. rubbers recently I don't see how it could have taken 4.5 hours just to do the front Iso. or why special tools were needed?
 
Last edited:
Joined
Oct 28, 2014
Messages
952
Country flag
A few small things were also done during that time as well as 1/2 hour for a sandwich. The main headache was getting the front iso in and out of the frame. Once it was out then changing the rubber stuff was easy. Also it was necessary to scrape out all the old rubber and rust getting to bare metal once again. The use of special tools makes the job so much easier. The line-up bars makes it very quick to fit the iso to the motor and frame and then to shove the bolts through by hand...no pounding or bending. No bent threads. Then the nut goes on with no trouble. As for R&R the rubber stuff, it can be done quickly and easily with a power tool, not so important with the rear which seems to be a push fit by hand. I like to make the job go easy and keep the frustration down as low as possible. If I have to do the job many times I will make tools for it. The time takes what it takes. also allow approx 1/2 hour adjusting the iso 2 or three times to get it right.
 
Joined
Nov 17, 2010
Messages
455
Country flag
If you upgrade from the shimmed ISO's to the vernier type there are two types for the front ISO. One that requires the engine mounting to be machined to make it the same as a Mk3 and one that requires no machining. The no machining ones are pretty difficult to fit back on to the bike.
 
Joined
Dec 13, 2010
Messages
413
Country flag
The adjusters developed by Mick Hemmings were easy to fit and easy to adjust, I like them.
Not sure if these are still available, or available from another source, since Mick is (semi) retired now.
 

L.A.B.

Moderator
VIP MEMBER
Joined
Nov 20, 2004
Messages
15,815
Country flag
A few small things were also done during that time as well as 1/2 hour for a sandwich. The main headache was getting the front iso in and out of the frame.
Ah, yes, well, downtime and attending to all those other small jobs that often present themselves as one goes along can expand the time considerably and perhaps should've been deducted from the 4.5 hours (unless the customer is paying?) ;)

Also it was necessary to scrape out all the old rubber and rust getting to bare metal once again.
I used a suitably sized flap wheel in a drill to clean out the tube. I don't think a flap wheel qualifies as a special tool, but..perhaps?
Edit: The new AN Iso once lubricated slid in with very little 'compression' required.

The line-up bars makes it very quick to fit the iso to the motor and frame and then to shove the bolts through by hand...no pounding or bending. No bent threads. Then the nut goes on with no trouble.
If the Iso is slid up squarely from below then it shouldn't take more than a little gentle persuasion as finally demonstrated in the video, below, although the rubber gaiters aren't fitted correctly in the video which perhaps made it slightly more difficult (and also why adjusting the Iso in the subsequent video proved difficult).

 
Last edited:
Joined
Oct 28, 2014
Messages
952
Country flag
I used the AN vernier isos , no machining required. The motor was supported by a small platform type jack so I could raise or lower it as needed. Once the front iso is removed the motor tipped slightly and moved slightly to one side. It takes very little movement to make it difficult to fit the iso. So out comes the lever and it takes a little trial and error to get the right combination to make things fit. As soon as possible I push the line-up bars into position, then home free. I try to do things carefully and gently. I ALSO REMOVED THE PIPES AND MUFFLERS. Perhaps another 1/2 hr to R&R the exhaust. I usually heat the head to make the ex nuts easier to remove.
Also notice it took him a while to get the iso started. He sped the camera up at this point. Don't know how much time it really took.
At $40 per, while-you-wait and drive it away I think it was a reasonable amount of time. This is with the customer standing around chit-chatting and observing the whole procedure from start to finish. Then he rode it for 10 minutes to get it hot, I tightened the ex nuts and off he went, a one hour ride to home.
 
Top