I see on here time and time again about using starting fluid on mower engine. DO NOT DO THAT. I have seen spark plugs blown right out of the head, mufflers blown off and even carbs blown out. Starting fluid has way too much kick for a small engine. And you will turn any engine into a "dope addict" by using starting fluid. You can take a brand new engine right out of the box and start using starting fluid on it and soon the engine will become addicted to it and will not start not matter what unless you use it. By the way I know my self for a fact of two people that got "shot" from using starting fluid. One used it on a chain saw and the spark plug blew out and went into his shoulder. The other one used it on a push mower. He got shot in the leg. Both had to go to the hospital. I would have love to have seen the X-ray techs face when he seen those X-rays.