I believe Magnum recommends 10% nitro fuel for break in, also some castor for lube. Do not recommend Saito/YS PowerMaster Fuel for break in. Once you get by the first gallon, use what you want. Before the first run, I also run some oil down the push rod tubes to make sure there is some lube in the cam area. A little extra top oil on the rocker arms is also a smart thing to do.

Good luck,

Chip