Yep, a bad riser will kill a 3.7. I got one in the garage that wasn't winterized and the riser busted dumping antifreeze into #4 cylinder. Took a little work but got it back running. If it ran hot Id check the oil, compression and antifreeze for tale tell signs. Sounds like your impeller may have gave up.
__________________
77 V20 cuddy with 170 I/O Mercruiser
72 16ft. Carolina w/a 25hp Evinrude
|