old johnson motor fuel ratio

[jwilkey84]

My grandfather has an old motor from the 50's or 60's and I was wonderinf if it is ok to run 50:1 in it? If not, what should we run. We have forgot what the fuel ratio is, and the tank is getting low!

 

[rickdb1boat]

Re: old johnson motor fuel ratio

web page

 

[phatmanmike]

Re: old johnson motor fuel ratio

officially, all omc motors 1964 and later require 50:1<br /><br />1963 and below were usually 24:1 since they used different bearings.

 

[JB]

Re: old johnson motor fuel ratio

Give us the model number so we don't have to guess, dammit.

 

[fishngal23]

Re: old johnson motor fuel ratio

I have a 1954 7.5 hp evinrude and the gas oil ratio is 24:1 phatmanmike is right.

 

[emdsapmgr]

Re: old johnson motor fuel ratio

You should be OK to run 50:1 in the engine. The only reason that older engines used 24:1 was that the oil specified was 30W car engine oil. Use a good TCW3 at 50:1 and you will be ok.

 

[JB]

Re: old johnson motor fuel ratio

Do not follow emdsapmgr advice.<br /><br />The reason the earlier engines STILL use 24:1 is that they have sleeve bearings that require a more oil rich mixture. The later engines use mainly "frictionless" needle and ball bearings.<br /><br />Follow MYOUTBOARDS advice.