For those of you that have experience with the 2 stroke mowers, is there a good fix for the stripped out notches for the height adjustment? Also if the engine revs extremely high where would I look to find the problem? I'm looking to buy a used one and these are the two problems that this unit has. Any other things to look for? It doesn't smoke and there isn't any abnormal noises to speak of. It will be my first one so I'm looking for help from experienced users only.