Home › Forum › Ask A Member › RD-17 crank defects—- › Re: RD-17 crank defects—-
I have a friend who is a racer, and he builds two stroke motors all the time at his professional shop. I have followed his advice as he has a lot of experience. Of course, any needle that has pits on it is junk. The crank can be another story. Each one is different. I can’t make out the damage in your photo too well, so what I will offer is that if the pits run in line across the journal, it is most likely not much good as the needles can fall into the groove. If there just a few pits, and they extend no more than 1/4th of the width of the journal, then the needle can bridge over them and not cause a problem. If I had one that had more than one or two small pits that could not be cleaned off with some emery paper, then I look for another crank. The idea here is that the needles will run over the top of a small pits and not cause a problem. The other factor is what is the expected service for the motor you are building. Are you going to run it WOT in Canada for an hour getting to the other side of big water, remote areas, or is just an occasional use motor for a cruise or two a season.
Steve