Posted by Gary Swart on July 17, 1999 at 10:25:06:
In Reply to: Stupid Yamaha question posted by Ron r on July 17, 1999 at 09:49:46:
First, no question is stupid. The model numbers of Yamaha, and as far as I know any make, has no relationship to bore size. According to the WBW catalog, the bore size of the YBB621 is .689". Hope this helps.