I have a 25 hp Mercury. Mid 1990s . I can't remember if it is 40 or 50 to 1 . My Evinrude is 50 to 1 , but I've only used the Mercury a few times . In Premium unleaded gas of course.
Thanks
Yeah, Johnson did the same thing with the 100:1 for a bit, it was a failed experiment.
50:1 is the way to go!
I have a 1997 25 horse Merc. I have used 50/1 ratio when I first got it. I used cheap Shipmate TCW3 and it smoked a lot. I went with Amsoil @ 100/1 for several years when i was on my Amsoil kick. An old friend that moved to Colorado left some Merc TCW3 in his garage. I took it and it smelled less than the Amsoil @ 50/1. As of about 5 yrs ago , I went with a 2 OZ . per gal . mix. ( 64/1) . With my old motor ( 1986 25 horse Merc) the manula said 100/1 was ok if used in summer and several times per week. I never noticed anything bad about any of the mixes. I still have my 1997 Merc and it runs perfect. Amsoil has run 300/1 mix and the 2 stroke never blew seized.
I agree 50:1, some older outboards, I would say 1970 or older did run 40:1, but a motor from the 90s will be 50 to one all day...