Then you need even less Nitro maybe even 0%.
Ya know they sell it.

I believe you need less than 3% oil with roller bearings, I'm not sure what the Tartan has.

So if 3% will work in your engine you will need to get the oil percentage to 9% and mix it with 2 parts gas.

You are going to have to do the math on this one I'd hate to be wrong