I have a 97 model fast strike 150 that has been a great motor, but a couple days ago I noticed a knocking sound while running. I did a compression test and the top 4 cylinders are around 110 but the bottom 2 are 85 and 95!! So I guess it is time to do something. How hard is it to rebuild one of these, I would like to do some of it myself to save a little money. Is it possible that it just needs a new ring job? Or is it most likely need to be bored out??just looking for thoughts!