proper fuel mixture

O

oldjohn

Cadet
Joined
Apr 16, 2010
Messages
16
I have a 1954 Johnson 5.5hp. Every old OMC I have owned, even my '57 Scott Atwater used 50-1. Four people have told me 50-1 is fine for this motor, one says it is 24-1... someone please set me straight so I don't FUBAR this motor. Info on where to find original paint colors and decals would be appreciated.:)
 
J

Jet Star

Seaman
Joined
Mar 14, 2010
Messages
69
Re: proper fuel mixture

iv read 25:1 is what they used back then but they just used regular motor oil because they didnt have 2 stroke oil back then so 50:1 should be the proper mix but dont take my word im looking for further clarification as well looking to start my '58 35hp soon and in the same situation as you
 
JB

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: proper fuel mixture

Jet Star said:
iv read 25:1 is what they used back then but they just used regular motor oil because they didnt have 2 stroke oil back then so 50:1 should be the proper mix but dont take my word im looking for further clarification as well looking to start my '58 35hp soon and in the same situation as you
Click to expand...

The mix ratio has nothing to do with old oil vs. new oil. It has to do with bearing types, clearances, etc.

You can take TX1961Whaler's word on that as gospel.
 
kenmyfam

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,385
Re: proper fuel mixture

Jet Star said:
iv read 25:1 is what they used back then but they just used regular motor oil because they didnt have 2 stroke oil back then so 50:1 should be the proper mix but dont take my word im looking for further clarification as well looking to start my '58 35hp soon and in the same situation as you
Click to expand...

Ah back in the days before 2 stroke oil. A lot of us were running "steam" outboards then.:D:D:D
 
F

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: proper fuel mixture

No matter what BRP says, and they didn't build the motor, that motor came with a four gallon tank. It says right on the tank to use one quart of oil per full tank. 1/2 pint per gallon. That is 16:1.

Beyond that, use whatever/whoever you want to believe. It's your motor.
 
O

oldjohn

Cadet
Joined
Apr 16, 2010
Messages
16
Re: proper fuel mixture

OK so 48oz oil for 6 gal fuel. is that for the 30wt AND the new 2cycle oils?
 
Captain Caveman

Captain Caveman

Ensign
Joined
Mar 1, 2005
Messages
924
Re: proper fuel mixture

Years ago, OMC began changing their recommendations, saying that you could run some of the older motors at higher ratios (50:1 and even 100:1). Then they made a dramatic back pedal and told everyone to stick with the original specs.

So, what should you do? Stick with the original specs. It looks like you need to be running 20:1 using an 2-stroke outboard oil.
 
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