I've purchased a used Sentar, 61", 25 hp in relatively good condition. I am having some problems with the cutting deck. The first problem is the outer and middle blades graze each other on a regular frequency. Every few thousand RPM's they rake past each other a few times and then they're clear again. It's an annoying sound mostly, but something's not right. The second problem is with the deck adjustments and leveling. At the 3" setting, I've adjusted the four chained deck adjustments almost all the way up and 2.5" is the highest it will go, and the left front chain basically has no tension on it. With this problem it's basically impossible to adjust any rake into it because any attempt at lowering the front on one side drops the whole side out of level. There appears to be ample adjustments in the threaded rods of the deck lowering arms, but there are several adjustmensts and I'm not sure which one to start with. It would be nice if there was a shop manual for these machines, but I don't think there is. Any input is greatly appreciated. J.P.