Originally Posted by GrandeGixxer

I was able to accomplish the 8 minute qualifiers with the Keep-Off 21-4. My runs were around 8:00-8:30 plus the half lap to get to the loop to start and I made it back to the pits each time. So I was getting around 9:00 of runtime. The motor ran good, I was able to get a pretty decent tune on it. Made it through the full 30 minute main, pitting every 7:30 and no flameouts.

What is the procedure for checking bearings, and how long do they usually last? This engine now has probably close to 3 gallons through it. I was sorely disappointed in this engine the first couple of gallons and for 6 or so races, but it impressed me yesterday. Maybe I won't make the switch to OS after all.