are you sure the cm6 plug is suitable for that engine? I tried a different plug in a china 52cc motor as suggested by some guys here on rcu but the throttle glitched bad and even stayed wide open. A couple other guy in our club experienced the same problem until they put the original plug back in and problem solved. Also some engines require 6v on the ignition...at least the Turnigy engines from china suggest that you use 6v and 93 octane gas. I'm using Penzoil air cooled also...good oil and I dont have to have 2 or 3 different gas cans sitting around with different mixes. my 2 cents

Ron