I have a 2002 Yamaha Raptor 660r and i just bought a new HMF Full-Exhaust, K & N airfilter and jets. How much faster will it be.

 

well, ur going to notice a huge difference in power and the length of gears will seem much longer. throttle response is going to be increased a lot also. id say 5mph or so top end, but much more top end power. i gained 5 mph with my slip on HMF

 

Do you think that i will be able to beat a stock Yamaha YFZ 450. With the stuff done.

 

It'll be close but probably yes...IMO

 

it will smoke you in the beginning but you will eventually catch up, i know this because i use to have the yfz stock and the raptor with the same mods and i would catch up.

 

you could beat a stock yfz with your stock raptor...(depends on the rider)

 

the question is can you find a stock yfz