Hello, I bought one of these SPE 40cc engines also from AK Models. Have had a few problems with it, but fired right up out of the box. The timing was WAY out of whack and the needles had to be tuned. I didn’t mind searching threw these forums and getting answers on how to set it up. What really bothers me is I am just now finding this subject on these engines. I wish I had not bought it now. The engine vibrates so much at low RPM's, I have to snug up the mounts every flight on my extra. I guess you get what you pay for. Should have bought a glow