Hi,
My name is Erika and my boyfreinds name is Matt. Matt has a 2004 Raptor 660. We recently purchased a full T4 exhuast and had a freind jet it. He called pro-circut and asked them what would be the best jet set up to run an open air-box, and a full T4, with a K & N airfilter. After changing the jets we realized that the raptor acually lost power instead of gaining it. So we would like to go back to the stock jets however our friend no longer wants to deal with it, so we are not sure of the stock jetting. If anyone is sure of the jets please let us know. Thanks.

 

I dont think i would run the stock jets with that set up, you are gona have to run it a lot fatter than that. deffinatly if you are running no lid with a kn id just buy a jet kit and it will give you a list of what jets you should use

 

its more than just the main jets to tune it properly

in your case,,,it may just be best to have a mechanic do it for you

should be cheap

 

Get a 160 and a 165 Mikuni main jet from your local dealer. Also get (2) 25 Piolit Jets. Install them, and you will be good to go. The Stock jets are 140/145, but if you install the stock jets and run the quad you will blow your engine guarenteed. take my advice! good luck

 

Hey thanks guys but we found what we need. The wheeler was running way too rich....which we already knew. Usaully your motor only blows up if its running too lean. But we contacted someone and we now know that we need 160/165 or 170/175 main jets. We already changed the needles, the carb springs ect.

 

cool

 

Sounds like ya'll picked up a DJ kit for it, changing the needles and springs, gald it worked out for ya'll