throttle lever... use a servo tester on it... or a tx/rx... but using a servo tester would be much better and mean there would be less to go wrong...
http://www.hobbyking.com/hobbycity/s...idProduct=8296...
This one is a bit bigger so may be easier to work with... http://www.hobbyking.com/hobbycity/s...dProduct=11780

just wire it up to the pot of a twist grip throttle contorl :)

what type of batteries nick? if you were to run 2 24v car batteries in series you would have huge run time... their about 70,000mAh!