I may have better luck on a cruiser forum, but I'll try here.

A couple weeks ago while running the genset I noticed a change in sound. I figured I lost the impeller and shut it down. Ordered a new one. Went to change it and once I took the belt guard off I noticed it wasn't the impeller, but it threw a belt. After some research I finally found the tensioner and was able to get it back on. During the process I discovered the pulley on the sea water pump doesn't line up with the other tow (most likely the reason it came off). After 30 seconds upon restart it threw it again. I see no way to move the pulley in or out to make it line up better. Anyone have any experience with this?

Is the pulley pressed on?

sounds like a pulley is working itself off???

Everything seems really tight. As far as pressed, bolted, whatever I can't really tell. There's a hole in the center of it, but I can't get me head down there far enough or finger in deep enough to see if there is a bolt. The whole things seems to be attached to the water pump. Like it's all one piece. The tensioner is on the same system. On the underside there at two bolts that allow it the entire assembly to slide back and forth. However I see nothing that would allow it to adjust in and out. Make sense?

I had to crack the paint to adjust the tensioner so it hasn't been messed with before. That gave me a clue to look if paint was rubbed off, cracked elsewhere to see the pump moving out of alignment. It's only got 80 hours on it.

I found this. It's the same model and running without a belt guard. Playing with the pause button it looks they're a little offset. Could be my eyes playing tricks though. It's the pulley just below and to the right of the oil filter.

http://www.youtube.com/watch?v=f67w0...eature=related

I know yours is in the bildge but how hard was it to change? going to do plugs and impellar on mine shortly.

I was playing with the pause button like you an saw a hole in the side of the pulley. Wonder if it has a lock bolt for the pulley in there ? I don't know but might be a great place to look. The pulley may adjust an could have a flat side on the shaft. Just a guess. Artie

I found a similar offset in a customers boat that I was changing the belts as routing maintenance, I wound up pulling the water pump and moving the pulley. I could get it closer but not perfect. My guess is your belt has worn enough not to be willing to overcome the offset. Try moving the pulley the best you can and use a new belt.

I kave a 9k kohler and the belt does not line up well either, but never threw a belt...hope that's not a jinx !!!