Problem with my rc buggy?

My rc Buggy is having some a problem the engine just wont start i took it out and removed the pull start and hooked up my drill to it put it on high and pulled the trigger. It didn't start. Now is it the motor? or my fuel? I think it is my fuel because its a year old and a mixture or 55% 20% and 90%. But if it is should i just unhook it from the fuel and let it run with the drill only for 1 minute to clear the pistons or the bad fuel? I know for a fact that engine is not bad because i only ran it for 50 Hours if it all added up i ran it either everyday or every 2 days. I blew my plugs twice so maybe i need more tuning to do? and buy a new plug. Now i have tried blowing the fuel back into the tank out of the fuel line to make sure there are no air bubbles blocking the fuel from going in. and i have tried putting my finger over the exhaust pipe and removing it while running the drill i have blew some nitro into the fuel line to the engine so that it might start? Any idea's what might be wrong??? PLEASE PLEASE PLEASE.