Ive used an engine degreaser. The best thing is to do what the others said about the glow plug,But i would also take the round side cover off and the carb as well,since the bearing/bushing is on the carb side of most engines. pour some of the degreaser in those points. and slowly rock it back and fourth.it will free up. Also its a good idea to rinse it out good after with degreaser.This has worked awsome and fast on any of my engines that were froze. Hope it helps. Brad