Running 24:1 Gas mix in a 50:1 rated motor

Detri Mental

Recruit
Joined
Apr 8, 2009
Messages
2
Hello everybody,

I have an old 1951 Johnson 5hp TN-27, and a newer 1982 Johnson 4hp. I would like to run both engines on the same trip and for the sake of simplicity just keep one tank of fuel mixed up on hand.

Is it okay to run the 24:1 fuel that my 1951 motor requires in my 1982 motor that calls for a 50:1 mixture? Will the extra oil gum or foul anything up?

Thanks much,

Robert
 

CATransplant

Admiral
Joined
Feb 26, 2005
Messages
6,319
Re: Running 24:1 Gas mix in a 50:1 rated motor

You'll be fine. The 4hp will smoke a bit more, but you shouldn't get any plug fouling or anything like that, as long as you have the right plugs in the 1982 engine.

I wouldn't do it for the long term, but it doesn't sound like you have that in mind.

Too much oil isn't a big deal. Too little is.
 

wbeaton

Commander
Joined
Jul 30, 2006
Messages
2,332
Re: Running 24:1 Gas mix in a 50:1 rated motor

Ditto. You could also gap the 4 hp plugs .005" bigger to avoid fouling.
 

coolguy147

Commander
Joined
Jul 14, 2008
Messages
2,817
Re: Running 24:1 Gas mix in a 50:1 rated motor

maybe do a more decarbs for both engines. it will help also. and keep extra plugs maybe just in case:confused:
 

Detri Mental

Recruit
Joined
Apr 8, 2009
Messages
2
Re: Running 24:1 Gas mix in a 50:1 rated motor

Thanks for the advice everyone. If I do go this route I will report back here after a season with my results.
 
Top