I just put a dynojet kit in my raptor, needels 4th notch from top, 144/146 mains, and fuel screws 3.25 turns out from seated(stock were 2.25). I also drilled 2 1" holes in the rear of the lid, and drilled out the stock exhaust past the baffel(a plate have way in the muffler)

from idle-1/8 throttle, it is fine, feels same as stock. then at 1/4 throttle it boggs, and sputters, as if it is running out of gas. then at 1/2 throttle on, it flies! way faster than stock.

Am I running too rich on the needels? It is about 20 degrees celcious, and I am at 200 feet above sea level. thanks.

oh, and the problen got worse as the bike warmed up. that is what makes me think it is running rich.

 

yea, try droping the needles down a notch,thats what would happen if your needles were too rich,not saying that is the problem but a good posibility

 

I agree..drop your needles one notch.

 

still running rough at 1/4 throttle. I tried lowering the needels and it ran no different . Less power from mid-top. so I put the needels back to 4th notch from top. tried putting choke on, sputtered worse. took the lid off, ran no different, a bit more sluggish on top. I covered the airbox lid holes and it was maybe slightly better. I put duct tape over part of the snorkel, and it ran like crap. sputtered everywhere. I am stuck. am I lean or rich? I don't know what I can do, any ideas?

 

0-3000' your suppose to be useing the 146/148 main jets. Tape up the holes put in the right jets and put needles on 4th groove from top. 3 turns out on the air/fuel screws.

 

my buddy chimmer has the same problem, He cant get the dynojet to work at all with no lid or one with holes in it. I think it has to do with turbulance (cv carb) or some crap.

He has changed everything and tried every combination, pilots and all, you name it he has tried it to correct his jetting. If you come along some kind of epiphany let us know!

His 2001 has full yoshi and no airbox lid..(proflow)

 

I am going to suggest something that is going to sound really stupid, but it happened to me, so go figure!!

My Raptor was sputtering terribly for me, and I didn't find it right away. I did all the big things, jetting, air screws and all that crap. Then one day on an MX track it just died!! Which forced me to look deeper. It would crank over but I had no spark. After thinking that my new engine had just broke, I gave my spark plug cap a firm push and MOVED!! It fired right up. With all of the pulling it off and putting it on while I was doing my plug testing, the rubber boot had slipped off the notch that hold it in place and also holds the plug contact in place.
The boot was below the notch, so it looked like I had it securely seated but the stem slid up and it was only getting intermitant contact with the spark plug. Hence the sputter.

Like I said, this sounds pretty basic, but those are the ones that seem to cause you the most trouble. Check and see if yours is loose, and that the triangle shaped boot is securly over the locating rib on the plug cap.

If this is the case, you can go back and jet your bike the way you had it before all this began. Ha ha

 

dynojet recomends 142/144. but since I modified my stock exhaust(with snorkel mod) I put the 144/146mj in. I'll keep trying and let you guys know. If worst comes to worst, I'm going to college in sept(no more high school![img]i/expressions/face-icon-small-happy.gif[/img]), and am doing outdoor power equipement(motorcycle) course. I can bring the rap down there and use their diagnostic equiupement. It is livable, but annoying. the power is soft, and sputters, then BAM! mid range comes on and lights up the tires. the powerband wouldn't mimic a banshee, but is violent for a 4-stroke. I just hope it's a rich condition and not a lean. Or hopefully an ignition problem like gregv said. Thanks for the replies, and if anything comes to mind, please post. I trail ride a lot and 1/4 throttle gets used a lot. Obviously, I could take it to a dealer and pay lotsa $$$ to get it fixed, but I need to save for college.

 

My bad, don't know why I thought you had an aftermarket exaughst. You stated what you had in your post. LOL. Good luck.

Maybe your problem lyes within your muffler. What did you say you did to it again?

 

I took out the spark arrestor, and if you look inside the end of the exhaust, you can see a restriction plate. I drilled 3 3/4" holes in it and put the spark arrestor back in. It should flow better than stock.