I have a stock motorcycle will i lose mpg if i jet kit it , take lid off air box and put exhaust on it?

Question

04 ninja 250 stock 400miles

Answer 1

Yes, you will lose MPG. If you are looking for power, look into changing sproket size. No need to go ???MPH. Get your power without losing to much MPG.

Answer 2

Absolutely will lose mpg.  Power versus economy. More power = less economy.  

Don't bother with it since you really need to run in the bike for a couple thousand miles before doing that kind of stuff.  You could probably spend the money better on a training course if you have never had one.