I am new to modifying anything let alone a quad. I installed my K&N Air filter and was told to rejet. Is the Dynojet kit any good?? Anyway sounds great after rejetting it but then bought a slip-on exhaust. Do I need to rejet again? And What should the jet size be? And what size sproket should I get and why do I hear about it so much? And should I get a high compression kit so I can smoke my buddies yfz450? What other stuff can I put on my quad? Thanks for the help and sorry about all the questions.

 

if your bought a good pipe you shouldnt have any problem smoking your buddies 450's

 

450's are pretty darn fast. I put a back GYTR pipe, K&N filter, and Dynojet jet kit on mine and it is reliably fast. Don't know if I can beat a 450r.

 

Ok here are the answers to your ???'s. Yes I would rejet with the filter and the Dynojet kit is the way to go. I do not think you will need to rejet because of a slip on exhaust. If you will rejet, it will be something small. You do not need a different sprocket with your set-up. If you change to smaller or bigger tires/rims or really go into the engine then you will need to change the sprocket. If I were you I would go with a full exhaust, get full skid plates, and save your money for a 686 kit...........JMO

Here is what I ran in my raptor with a full exhaust:
Main jet: 148 / 150 DJ Needle/Clip position: DynoJet / 4th Pilot:27.5 Fuel Screw (from closed): 2 +/- 1/2 turn

 

yes you will need to rejet . before u throw all this money on this bike to smoke ur buddies watch what u do dont go to radical or ur reliability will go way down trust me i am on my third rebuild. dont get the real radical cams and dont go to high wit compression i am running 11-1 know and it seems to be fine so far

 

As mentioned you will need to rejet.AS to what size I have a full Yosh a KnN and 2 holes drilled in air box and removed snorkel I am running 150/155 jets. I am running stock gearing with my mods and dont have any trouble pulling my buddies modded YFZ as well as others.Now there will be those who say it cant be done,but we are equal riders,we have switched quads,and I was beating his when we were both stock as well.Maybe my raptor is just possessed.Good luck.