Av8tor - I read a post from a couple years ago where you were going to make thrust washers for a 21cc Mac blower engine that had needle bearings. I have the same engine that was on a weedeater - Mac 60sx that I was beginning to convert when I noticed the roller bearings and found your post in a search. Was your project successful and did you use the McmasterCarr thrust washers? Anybody else successfully convert this engine. The one I have is extremely clean with almost no sign of wear. It is so light and compact it seems perfect for gas/glow conversion except for no ball bearing mains.
Keith