Hello, I have a 1960 Johnson Seahorse 18 hp that I use 24:1 gas oil mix in. I just picked up a 1961 Johnson Seahorse 18 hp. My question is, does this motor also burn 24:1 gas/oil mix?
Yup. They did that up until 1963. In '64 they switched all their motors from 24:1 to 50:1.<br /><br />Old OMCs are addictive, huh?<br /><br />PS - Have a look at this page from the '61 catalog:<br />Page<br />I belive that the small end connecting rod bearing was the last one they changed from plain to anti-friction.
Thanks..... The guy I got the motor from told me he burned 50:1 in it for the 1 season he had it. He said he "just assumed". How much damage could this have done to the motor? It seems to run fine, I've watched the guy run it on the lake I live on.
Probably none at all. There's not much difference (mabey no difference) between the '61 engine and the post-63 18hp engines that ran 50:1 spec. <br />But there's no good reason to run so little. If you want to reduce smoking, try a synthetic 2-stroke oil instead of reducing your mix.<br />Check out the Oil Mix FAQ in the FAQ forum for more information.
Great, thanks. I'm hoping to put both 18's side by side on my 1955 14 foot Tomahawk. Yes, old OMC's are addictive. If I bring home another boat (or motor), my wife is going to kill me.
