Don1977 605 #1 Posted January 19, 2012 I know that 10 , 12, and 14 HP are usually 11 fins engines with 9 head bolts. The 16 HP engines have 12, and 13 fins with 10 head bolts. When counting fins is the very top under the head counted, as it would be a one sided fin. Share this post Link to post Share on other sites
Don1977 605 #3 Posted January 19, 2012 I have a 12 HP 9 bolt head with 13 fins it has E 1 6 cast in the block. How often does this happen. Share this post Link to post Share on other sites
