Peg vibrations

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Jan 18, 2006
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I want to say thanks for all the usefull input to this forum. My 850 mk11 Interstate seems to come up with quite a few little faults these days but you guys seem to set me in the right direction to fix them.
Just replaced the clutch hub which had 2 nasty grooves causing clutch drag changed the front drive chain sprocket at the same time.
Went through the points and capacitors did a thorough tuneup. She is now running like a rocket. I hope it lasts more than a few days. use to be the tune would fade off after a couple of rides.
One thing i now have is more vibration at the foot pegs. Any ideas?
I'm thinking the Primary chain may be a bit tight?
Anyway thanks for the great input
dg, how much does it vibrate when idling, you also say the tuning disappears after a few days, have you made sure everything is tight in your ignition timing including the coil primary wires etc. You might try Iridium plugs they tend to hide a few sins.
vibration and tuning

The tuning used to fade off after a couple of rides, I put it down to worn carby's. So replaced them with new amals, then thought maybe the capacitors were causing the points to burn & pit so i've replaced those and also new throttle cables so i'm waiting to see how she is in a week or so.
The vibration is just a niggle of irritation at the foot pegs that wasn't there before i changed the clutch. The engine is running pretty smoothly now.
Started first kick this morning.
Thanks, David


I remember when still using points the tune would go away after a couple of weeks. Make sure to lube the automatic advance weights behind the points plate. Electronic ignition will eliminate this.

No way to tell from this side what's causing additional vibration. Isolastics tightened recently?

The isolastics have never been touched. I guess i've always avoided them especially the rear mounting In my mind its in the too hard basket.
I have tried to measure the front mount which seemed to be within spec at the time but the method of measuring it seemed pretty crude to me. Lever the engine over and insert a feeler guage in between the shims, according to my manual.
Mark iii iso's sound the way to go. Are there any easy methods for the MKii's ?
Isolastic adjustment

Hi David,

The front adjustment is easy enough. I usually take the whole thing out, put it in a vise and check it. The rear is a pain. What wears to make the adjusment gap wider is the polyurethane discs, and they do wear. In your case where you have more vibration, the isolastic adjustment does this if too tight. The vernier adjustable MkIII is a nice way to go, but I have not done that yet on my '72. It's expensive.
I guess i've always avoided them especially the rear mounting In my mind its in the too hard basket.

DG .. I too looked at the rears with a lot of distaste.. until recently I had similar dramas to yours and I bit the bullet as it were ~ to check them was not nearly as hard a job as I thought.

Now if your'e going to over haul them.. hmm. ~
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