Aircraft operate under very different conditions than Motorcycles used in Racing, and the fuel requirements is very different as well.
Aircraft engines run within a very narrow rpm range. There's no need for transient throttle response in an airplane because after the initial engine run-up, the throttle is set in one position and the rpm doesn't normally change until landing.
Airplanes fly where the air is cold and thin, and the atmospheric pressure is low. These are not even close to the conditions your Motorcyle will see on the Race Track. Most piston-driven aircraft cruise at 3,000 rpm, the burn rate of Aviation Gas is much too slow for any high performance Motorcycle Racing applications.
In conclusion do not use Aviation Fuel as an alternative to Race Fuel.