The Stovebolt Site Forums The Shop Area The Tool Chest Two Cycle Engine Oil

I was told a long time ago that 30wt motor oil could be mixed with gasoline for use in 2 cycle engines. Is this true? Was it true in the past when 2 cycle engines were "less sophisticated?"

Just wondering because I never seem to have the 2 cycle oil when I need it but always have lots of different motor oils handy.

The old outboards from the 50;s as well as chainsaws used 30 wt oil but the newer 2 cycle oil is way better and for what it takes to buy a gallon and put it on the shelf I would not use 30 wt .

One of the most expensive mistakes I made was running one can of "generic" 2 cycle oil in an Echo chain saw- - - - -locked up the engine before I used one tank of gas. That one cost me a new crankshaft, and an oversized piston. I was able to save the cylinder, but it had to be honed out to fit the bigger piston.
Jerry

Yes, there are 2 cycle oils for air cooled engines like chainsaws which are somehow different than the oil used in water cooled outboards.

I've got a 1949 Scott-Atwater 7 1/2 HP outboard stashed away in the barn. The fuel/oil mix instructions are "1/2 pint SAE 30 non detergent motor oil to 1 gallon of gasoline"! When I would go fishing with that one, the skeeters on the lake didn't stand a chance of surviving! It's got two threaded bungs under the cowling for spare spark plugs. They fouled out pretty frequently.

Unless you're using a fair amount you might want to buy can of premixed fuel. You can find saw manufacturer branded or generic . Local farm store should have a good selection.

My 1955 Johnson 10hp has instructions on the cowl for a sale 30 mixture but I have always used a outboard oil at about 40 to one mix and it has been good had this one from my teens.