Potential project

[A RC Dude]

ok, a friend's family at school bought a 25cc leaf blower but got tired of trying to crank it, paying for fuel, all the normal gas engine stuff and bought an electric one without using the gas one much at all. they were about to throw it in the dump and my friend knew i like to build stuff so he gave it to me. The engine looks bran new, even on the inside, but i feel like making some kind of basic, very cheap, fast, on road/baseball field type RC car, probably without any kind of suspension, out of it. But the biggest question is how to do the drivetrain. the shaft comming out of the motor is 7mm thick and has a flat spot.

All I am planning is to basically to slap the engine, tires, gas tank, and very basic steering system on a peice of steel, i don't have much money, don't plan on going off-road (maybe a flat dirt field) or hitting any bumpes at speed. But i have a few questions:

1. Would a Baja pinion gear be the right size? i can't find the I.D. of it anyware

2. Would i be able to do a direct drive from the pinion to a spur and out to the tires, without a clutch?

3. Would cutting the engine off work as a decent brake? i'm not looking for much and i wont to keep it lightweight

4. What kind of tires/driveshaft could i use?

5. What kind of speed would that give me and would it have enough torgue?

6. Would i be able to use a steering servo that doesn't cost much?

7. Could i even build it only using a drill press, grinder, and my friends band saw that can cut metal?