Is this the ringed or ABC version?
For Ringed -
We recommend that you mount your engine to a break-in stand to familiarize yourself with it and with the carburetor operation. It is strongly recommended that fuels containing more than 10 to 12% nitromethane be avoided until the engine has been operated about one hour, for the initial flights adjust the engine to a slightly “burbling” sound and a smoky exhaust. After each tank of fuel, the engine can be “leaned” until about one gallon of fuel has been consumed. For both break-in and general operation K&B 500 should be used.
For ABC -
see this page http://www.mecoa.com/kb/61/og-6150.pdf
The MECOA.COM site is full of info on K&B; they make them.