I suspect the correct thing to do is to run it as loose as is possible without it ratcheting. If it does ratchet, tighten just a little and try again, until it stops, then measure the deflection and use that as a guide.
I can't help wondering if running the belt too tight is the cause of BB whine, as Micheal suggests. If this is the solution, it justs sounds to easy after all the problems that eveyone has suffered.
This is where we need Mark Evans, or maybe another Mark, to come onto the forum and explain why it needs to be tighter and what work they have done to overcome this problem.
