I ran the first 4 tanks through it last night, went great, not a single flameout or hiccup. I had to preheat to about 240 before it would turn over enough to start, and in the past heating up to 250 if needed has not hurt anything.

Agreed on running temp, but I try to keep it above 220 and closer to 240 during breakin to be as gentle as possible on the conrod. I either use tinfoil or my Comp Heat to cover the cooling head to keep as much heat in it as possible while running it really rich on the first several tanks.

Also agreed on 8mm venturi, easier to tune during rich breakin. Try racing the 8mm restrictor before you switch to the 6.5, I have started running it all the time that way and love it on the old 2needle carb, we'll see how it works out with this 3needle. Seems mean as always so far!