In 4th and 5th gear and at about 3/4 throttle, my Raptor surges, spits and sputters until I back off the gas. I have the Pro Design 2 stage filter with unmodded air box along with a White bros. e series slip on with 12 discs. I'm running with dyno jet 144 and 146 mains with the needles set on the 3rd groove from the top. What do you guys recommend? Oh, forgot to mention that my Rap doesn't have the acceleration that it used to have either. Thanks for any help guys.

P.S. I have already cut out the flaps in the snorkel.

 

Anyone please?[img]i/expressions/face-icon-small-happy.gif[/img]

 

Well i think your lean, but to be sure check your plug! i would go up in your main jet to the next size, also i would buy some pilot jets try the 25. its my experience that the raptor is major lean right from the factory!!!

plug chart: white=lean ,blk&wet=rich light brown perfect

01 blu660r
pro-design kn
150-155 mains 25 pilots
with all the other goodies

 

a good rule thumb if you have a problem when
asking for horsepower, the problem is rich. if you have a problem wen not asking for horsepower , then you are lean.

 

The center electrode on my plug is white. There is very little carbon on the edges of the plug.

 

surging on top end ussaly means lean ,and your plug reading enforces that I would go up at least two jet sizes in the main and up one on the piolet side ....good luck

 

mine does the same thing i just went up on the main one size from the stock one hope this helps

 

Dan, are you sure thats a stage "3" kit? I was unaware there was such a kit. I am familiar with the stage "2" kit. The directions call for the clip to be installed in the 4th clip position from the top. If in fact your kit is a stage 2, then this could be cour lean condition......

 

there is no stage 3 kit (and stage 4 not a commercial raptor kit but would include an open airbox), probably a typo, sounds lean, I would go up on the mains, drop the clip to the #4position, and go up to a 25 on the pilots. one other item though if your location calls for oxy fuels in the winter (they add up to 10% ethanol to the gas at the pump from nov->march) you could encounter the same problem, if that is the case change back to the stock needle till march when the stop the oxy/fuel programs

 

You're right, I do have a stage 2 kit, I didn't realize it till I looked at the box. I'll go up to a 148 and 150 on the mains. Where can I get pilot jets? One thing I've also noticed is when I over oil the foam filters, the bike seems to lose acceleration and the surge gets worse on the top end. Thanks