20:1 in '56 Lightwin ?

[kyron4]

I have a 1956 Evinrude Lightwin 3hp that runs like a champ. I have always ran a 20:1 mix. I've read here that 24:1 is all I need. My thinking has always been that little extra oil will lube the bushings a little better for longer life. Does it even really matter ? Are there any benefits from running 24:1 vs 20:1 or vise versa ? -Thanks

 

[1946Zephyr]

Re: 20:1 in '56 Lightwin ?

Those are actually recemended for 16:1 (1/2 pint per gallon) as stated on the decal for oiling intructions. 20:1 is okay. Some here will say 24:1 is fine, but 24:1 is actually the recemendation for the bigger motors with needle bearing crank and rod assemblies. The smaller motors, such as the 3's, 5.5's and 7.5's all specify 16:1 from the factory and these three models are 100% friction based motors.

 

[kfa4303]

Re: 20:1 in '56 Lightwin ?

Zephyr is right, go with 16:1 per the instructions on the motor. These older models need a bit more oil. Better to have a bit too much oil, than not enough and have the motor seize up on you.

 

[kyron4]

Re: 20:1 in '56 Lightwin ?

So bumping it up to 16:1 will have no ill effect on the motor or preformance (lower rpm,excessive smoke or carbon build up ) ? I remember reading that the 16:1 rateing from the 50's was with the old S.A.E. 30 motor oil and with the better TCW-3 oil of today that not as much was needed. This is why I went with 20:1 its half way between 16:1 and 24:1 , I just split the difference. I have no proble adding more oil if it doesn't effect preformance or motor life. Your thoughts ? -Thanks

 

[kfa4303]

Re: 20:1 in '56 Lightwin ?

It shouldn't really effect the performance aside from a bit more smoke perhaps. I know what you mean about the new oils being much better than the old stuff they used to use, but I would still err on the side of caution. While the oil is new, the motor is old and old motors like plenty of lubrication. Just my 2 cents.

 

[1946Zephyr]

Re: 20:1 in '56 Lightwin ?

Oh you bet it will smoke more. You'll wipe out the misquito population in your neighborhood, if you put that thing in a barrel. but that's okay. all motors did that prior to 1960, because of the heavier mix. That is also why these ran the J6C or J8C spark plugs, so the performance wouldn't be affected. My little Johnson HD-20 calls for the J8C plug. The bigger motors, that run on the 24:1 mix generally call for a J4C plug. I don't like the J4C's though, so I run a J6C in about everything I have, when it comes to old OMC's. Eventhough the new TCW-3 oil is better than the previous type oil mix, I still go with the factory recemendations. One thing to do about carbon build up, is to sea foam your motor every other year or so, to get rid of it.