Hello all! I would like to start this post off by saying I am trying to get a go kart build rolling. I bought a harbor freight engine (predator 212cc) after researching and seeing the great price and users positive feedback. I have run the engine a few times to break it in but here is where my dilemma begins. Just last night I was fooling around and took off the exhaust and ran the engine (I know not a smart decision). It made a bubbly noise untill I turned it off. When I put the exhaust back on and tried to start again I noticed that the pull cord would snap back and was hard to pull every few pulls. I have been looking around and seen that it may be a timing issue with the flywheel and woodruff key may be sheered. I am getting the tools to take off the flywheel to check. In the mean time I wanted to ask if anyone has any other ideas on what could be happening. Thankyou!