I had a similar problem. I want to say that there were 6 balls in there, but I could only find 4 or 5 after the thing blew up on me (I knew I was missing some, but couldnt tell how many.
I was able to get it to sort-of work, and after a while I found the exact part on ebay for like $10. I just checked and there are none on there now, but if I recall the whole assembly was not terribly expensive at Torreson marine.
-dan
