ORIGINAL: Four Stroker
I am always amazed at the damn fool crap you can read on forums. Some of the people responding are ten and have never owned an engine. Most of the people responding have never owned a YS engine. You get the answers from 40 years ago - C.F. Lee. YS engines are full of silicone rubber seals, O-rings, diaphragms. Performance Specialties (Dave Shadel) AF oil is specific to YS engines. Mobile 1 and Mobile 1 pure synthetic ATF will not harm silicone but may not be a good after run oil. Castor ? Really ? Richard Verano loves you guys since half of his business is repairing engines that were pumped full of after run crap.
Four Stroker, I have to agree with you. It's really something to see so many self proclaimed experts with all this advice that they have little or no knowledge about.
I ask, are there "o" rings in the fuel injection system of a car? Are there rubber, silicone seals, or diaphrams in a automobile transmission?
Now I ask, are there "o" rings in the crank case, air passages and combustion chamber of a YS or any other 2 or 4 stroke engine? Did anyone say to run the after run oil through the fuel lines? Does Castor Oil have rust inhibitors in it? Does Castor Oil gum up after sitting up?
Everyone has their own formula for making after run oil. From mixing ATF with Castor and ATF with Mobil One.
Marvel Mystery Oil has been around for a long time. Ask the owner of a 1939 Cub if he uses Marvel Mystery Oil in his fuel and oil? 9 times out of 10 he will say that he does.
I've got engines that I am still flying that were made in the 70's. Still running strong and all had Marvel Mystery Oil used as an after run oil.
So, If they have lasted this long, then I will continue using Marvel Mystery Oil.
Maybe it's disolved all the "o" rings in my crank case. Because I haven't been able to find any in there.
Frank