How can you make a 1994 Honda XR80R Dirt bike go faster and run better gust by tunning the engine with tools and not having to buying parts?

for starters, you could take out the head and port and polish it. then if you want, you can take the spark arrestor out of the exhaust pipe. less restriction. a cheap upgrade would be a k&n airfilter. you can get those for your bike for i think like 20 bucks max. the reason i know is because i have this bike. im a 14 year old kid who had to do this on my own so i could race it. after you get into it. you can put a bore kit on there. upgraded cam's, etc.