jayseas,

I don't think ANY glow engine will run with 50% oil.

You can run your .15 and .19 with the fuel as is, but it would last longer with about 22%-25% oil. I like 22%.

The Fox .35 is another story. As I mentioned in the other post, it likes 25%-28% oil.

Unless you are racing, you do not NEED 25% nitro. It will run in the .15 and .19 (never tried that much nitro in the .35) , but you are wasting your money. You could add both castor and methanol to bring the nitro percentage down to your 17% range.

George