OK, I talked to Cen and told them my problems. they told me to send them the motor back, which I did. I got the motor back 8 days later, pretty quick turn around fromn texas to calif. and back to texas. The only problem is they did not fix the problem. The motor still does the exact same thing. The tech. that I talked to wed. said that they ran and tuned the motor on the bench and that it was ready to drop in and finish break in. The peice of junk wont even run!!!!!!!!!!!! I have tried to eliminate every possibility other than the motor but I cant find anything else wrong with anything. I checked all fuel, tank, glow, and exhaust possibilities. Tomorrow I will put a proven .26 on my matrix and see if it works.