Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

@Jim

Hey Jim, I seem to recall you asking about the proper mix of oil to petrol for running any of Jin's gas engines. I think it was right after you finally managed to source some Marvel Mystery Oil (MMO), and were wondering how much to mix in.

I was just looking through the instruction sheet (how rare is that?) for one of Jin's smaller H&M engines, the M17, which seems to be a smaller version of the M90 that he brought out first and many of us got our first taste of H&M on. In those instructions, he specifies a 3% oil mixture for the fuel on that engine. Don't know if that is a universal recommendation (probably) but it certainly doesn't specifically mention MMO, so that may want a different mix.

Seems to me I recall answering your original posting (which I currently can't find) with something like 40:1 as typical of what I use, which isn't too far off from 3%, though I'm none too scientific about mixing it. Also adding, if your exhaust isn't showing any oil, add more, and if it is running really oily, add less, or some less than specific description like that.

I stand by those answers, but YMMV?!?!

I always take Mystery Oil coming through the exhaust as a good sign.

With cooler running engines, MMO doesn't burn much at all vs 2 cycle oil which is designed to burn.

Yes, Jim, it does smell quite nice compared to alternatives.