First make sure all of the screws, bolts, fittings, and anything else that come apart are tight. On one of my brand new 55AX engines the head bolts, backplate screws, carb screws, needle valve seat, and even the fuel line nipple were all loose from the factory, which was causing frequent deadsticks.

Tightening the parts cured about 99% of the deadstick problem. Switching the glow plug to an OS F plug cured the remaining deadsticks.