this is a good thread.i ran the Valvoline VR1 because it was high in zinc & locally available.also i was running 20/50 (under protest of coarse)because i had pressure problems when hot.i freshen up the motor this winter, I'm gonna ask the fella @ the machine shop what weight he can suggest to complement his handy work..i saw Joe Gibbs oil on the shelves over there but i'm sure there's a bunch of good ones out there too.