I rejetted my 02 raptor last weekend, here's what i did:
02 raptor all stock, @ sea level
installed a k&n and cut the flaps out of the snorkel
142/144 (smallest jets that came in the dynojet kit)
needle on the 4th clip
dynojet slide springs
pilots 3 turns out
On my test drive I was getting a slumble at low speeds when I would goose it.
It would also get worse as the bike got hotter, classic rich condition, so I moved the needle up a notch.
Test ride had the same results but the stumble was ALITTLE better. I then when another notch.
Test ride was the same. I then moved it to the top notch. The bike did run better but the stumble was still there. I called Dynojet and they said my k&n was over oiled. I cleaned it and while I was waiting for it to dry I put the stock filter on and pulled back the foam alittle and ran around my yard. No difference.
I then checked my float level and found it was approx 3/4 above the float bowl(nice job Yamaha!) I adjusted the floats to factory spec. and put my needle back to the 4th clip.
Now the stumble is alot less noticable but still there. It feels like a Quadrajet carb on a car, just a slight hesitation when you nail it at low rpm or when you fliff the throttle. I moved the needle but it stayed the same.
Does anyone else have type of throttle response with thier bike. I've heard thats how raptors are
Thanks for the help

 

here's what i did maybe it will help. i put 150/155 mains and left the screws stock. i have no ari box lid but i cut the tabs for when i leave it on. the needles are at the fourth notch down and i only oil the outer sleeve of my k&n....also what elevation are you?..im at about 4000-4500.

 

Why are you oiling a K&N filter?? isn't is a paper type (I know its not paper) More like a car filter ? Or did you get the Prodesign proflow kit with a 2 stage oiled filter.

 

Raptorahole,

Take the vacume cover off the top of you carbs. Check and make sure the jet needle holder is still in place and has not come loose or off completley. This will give you a rich condition at idle and just above. I rejetted once and had a bad stumble at off idle and was fine when WO. Maybe the needle holder was not inserted all the way and seated properly. Give it a look see.

rraptorr13,

K&N filters must be oiled prior to use or they will not filter properly. K&N filter oil not foam filter oil.

 

Needle holders fine , I'm always scared thier going to pop off. Chickensh*t design but they seam to stay on.

Yes I do use k&n oil not foam filter oil...

How do you install the holders..I just push them down and move them around 'til they sit straight. Are they suppose to pop or snap in?

 

with the k&n make sure the gasket they gave you that you stick on the airbox is not blocking the opening, I am suprized you would be rich with those jets at sea level, try putting your stock jets back in and see if the problem is still there, if so the problem is most likely the needles or your float bowl
raptorider420: "i only oil the outer sleeve of my k&n." what outer sleeve? I hope you dont mean the outerwear

 

I believe that you need to turn in your fuel screws (some call them air screws) a full turn on both sides. Actually I would turn them in a quarter at a time and test.

KD

 

Isn't the pilot screw the air screw on the carb.

 

Raptorahole,

The way you describe it is how I install my needle holders. Ive never noticed it snapping into place. I just push it in all the way and try and line it up strait. Somtimes it looks crooked so I move it around till its strait. Yes, it is a chicken sh?t design.

Rraptorr13,

Its called an air screw if the screw is on the airbox side of the carburator, and its called a fuel screw if its on the head intake side of the carburator. Depending on what side the screw is on will determin what you are adjusting. The air mixture (increase or decrease) with the fuel or the fuel mixture (increase or decrease) with the air. On the Raptor carb it is the fuel mixture with the air.