I am having trouble adjusting my blade tracking _ am almost positive my main shaft is not bent, and I replaced the spindle. If I adjust the link 1/2 turn on the high blade it is then lower than the other one - I could get them perfect before! How much would be aceptable - 1/4 - 3/8"?? What else could be causing this - also, what are the o-rings where the spindle goes through the head for?? Can they be replaced with bearings?

Another question - can I replace the flybar with same sized piano wire, or will it be too flexable?? Could a slightly bent flybar keep me from getting perfect tracking??