It turns out that I did need a new rear bearing. I found a good German bearing of exact specs, although I took the seals off of it. I was surprised that the OEM was a sealed bearing. Anyway, big difference now. All of the RPMs are back.

Here is another situation. On dissasembling the motor, when I removed the airvalve, the little plastic insulator stayed in the crankcase. I pulled it out, but I noticed that there was some sort of adhesive that originally held it to the air valve. I got a nice tight fit when replacing everything, but I had to tighten the airvalve retaining screw more than normal to keep the airvalve from turning. What kind of adhesive can I use to reglue the insulator to the airvalve stem, or do you think that as long as it does not turn I'll be OK?

Also, is it possible to get a replacement insulator without buying a whole air valve. I do not see that individual part listed a Tower, and the airvalve itself is very expensive ($375.00).


Thanks for your assistance. I know that these motors do not bring the easiest answers.


Mark