I've had issues with this bike with it running on one cylinder. I've talked about it here and there is a thread on the topic. I think what I'm going to bring up here is related to the issue.
Several years ago, during a troubleshooting expedition, I removed the carbs and found one of the insulator spacer o-ring grooves broken thru. I had a spare and replaced it. Today, when I pulled the carbs, I found the same thing. Actually I found one broken thru to the outside in exactly the same place (had saved the old one) and the other had the o-ring pinched between the insulator and the head. O-rings on both carb flanges were perfect. Here are some pics.
Here is the insulator I found today and the one I found a few years ago. Note that the failure is identical. The one with the light tan facture surface is the one from a few years back.
Here is how today's find looked when I removed it from the engine.
Here is what the undamaged insulator looked like with the o-ring trying to escape.
So, my first question is how necessary is that insulator block? Can I machine new spacers from aluminum and be done with it. Or is there enough heat conduction thru the carb flange that I need those insulators. I'd prefer to eliminate the o-ring against the head and just use a gasket with an aluminum spacer.
I suspect that the O-rings, which were sourced locally, may be expanding from exposure to gasoline. I think they are nitrile, not Viton. I may have also put in a size that was a tad too big and expansion has caused them to burst thru the side of the insulator. Both were broken where the numbers are engraved, which makes for a stress riser at that point.
Anyone here have spares they'll part with? I need one. Being Sunday, I won't know if I can find them with dealers or vendors until tomorrow, and may have to wait until Tuesday since many shops are closed on Mondays.
Thanks,
Rob
