i put on a hmf full system, and a k&n air filter , on the hmf web sight it says you dont have to re-jet , but i put on a k&n filter i was wondering if that is enough to rejet. would it just be safer to just go ahead and rejet and what jetkit do you recommend? thank you

 

How does it run now? What color is your spark plug? That will tell you a lot about how you are now jetted. Have you also drilled or removed the airbox lid? To get the full benefit of your pipe and filter you should also get a jet kit. You could save some money and just try some larger jets, but if you order a Dynojet jet kit you will also get a different tapered needle plus different sized jets and the instructions will get you pretty close to right the 1st time. Shipped, it should not cost you over $50.

 

it runs ok but when i slow down or start to come to a stop it will pop and back fire constintly. should i not ride it until i rejet?

 

You need to rejet.more air in , more air out along with some more gas will give you more power. I added a uni-filter with 5 or 6 vents in the air box and a white brothers exhaust. I bumped up on size on the pilot jet and went all the way up to a 112 on the main jet. Save your self some money and just go to your local dealer and for 4 or 5 dollars you can get the jets. I'd lay off riding until you jet up. Dont want a hole in your piston!

 

The pop and back fire on decell are signs of a lean idle circuit. If you dont have an intake leak, then just richen up the idle circuit by turning the mixture screw,ccw, a 1/4 turn at a time, til it goes away. If you get to 4 turns out from lightly seated, then youll need to go one up on the pilot jet.
How does it run when wide open? Missing, or sputtering?

 

i havent took it out riding yet ive only rode around the yard so i dont know how it runs up high or full open. ive never rejetted before. should i get a jetkit or just buy a jet from the dealer? thanx

 

The individual jets, run about 5 bucks each, at most, youd need 3 of them(one up on pilot, and one and two up on main), im not sure what jet kit youre looking at, but im sure its more than 15 bucks.
There are lots of places online to buy from, if your dealer doesnt have what you need.

 

ok thanks for all of the advise guys i guess ill go to my dealer to get the jets to save some$$$$