I agree Pat, but in this situation this engine had VERY weak compression, so weak that it would have wind milled freely if it died in the air. I don't think the original poster was looking for any numbers, just some kind of comparison to see if his engine was healthy and whathe could do about it,believe me, it was not healthy. Do I see some more extensive testing to come up with some baseline compression stats on our little engines, can't think of anyone more qualified to do it, what do you say?