when i put the engine on full choke, crank it over about 10 times, it starts and smokes ALOT and runs for about 30 seconds if i blip the throttle, then if i put the engine on half choke while its running, it runs smoother and dosent smoke out of the muffler, but then after about 3 seconds it dies. and its literally IMPOSSIBLE to start it on half or no choke. the engine has great compression, a good working spark plug, and for now no air filter on it. your help will be greatly appreciated thanks.