I know this is a topic of many forums, but my problems is a little different. First of all I have an 02 raptor with 11:5 wiseco piston, all around, cam porting by local shop, and pro-flow intake with K/N filter no air box lid. I'm trying to figure out if my problem is in the jetting or somewhere else in the carb.My jetting is 175/180 needle clip as low as it will go stock pilot and fuel screw 2 3/4 turns.

My problem is my Raptor runs great on flat ground but on an incline it doesn't fair so well.

For instance we went to Little Sahara OK on Memorial Day out on the flats it ran fine. But you would get it out on the dunes it would cut out and die. If you stay in the gas it doesn't do it but the second you are on a incline and have to let of the gas for a second it will start acting up. If you are spinning a donut or trying to climb a hill and go from 3/4 to 1/4 throttle it will start sputtering and try yo die. But this is the only time it runs even remotely bad. Some people have suggested adjusting the float but before I tear into it I thought I would get some insight on what you guys think the problem is first. Or maybe I need diferent Pilot jets. PLEASE HELP ME!!!! It is making riding very unenjoyable.
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<< I know this is a topic of many forums, but my problems is a little different. First of all I have an 02 raptor with 11:5 wiseco piston, all around, cam porting by local shop, and pro-flow intake with K/N filter no air box lid. I'm trying to figure out if my problem is in the jetting or somewhere else in the carb.My jetting is 175/180 needle clip as low as it will go stock pilot and fuel screw 2 3/4 turns.

My problem is my Raptor runs great on flat ground but on an incline it doesn't fair so well.

For instance we went to Little Sahara OK on Memorial Day out on the flats it ran fine. But you would get it out on the dunes it would cut out and die. If you stay in the gas it doesn't do it but the second you are on a incline and have to let of the gas for a second it will start acting up. If you are spinning a donut or trying to climb a hill and go from 3/4 to 1/4 throttle it will start sputtering and try yo die. But this is the only time it runs even remotely bad. Some people have suggested adjusting the float but before I tear into it I thought I would get some insight on what you guys think the problem is first. Or maybe I need diferent Pilot jets. PLEASE HELP ME!!!! It is making riding very unenjoyable.
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I believe what you are experiencing is cavitation, which is simply the fuel sloshing in the bowls on steep hills or hard cornering. I don't see how changing the pilot jets could help since you say the problem occurs at 3/4 throttle or above; the pilots operate at idle to 1/4 throttle and again at full throttle.I'd think raising the float levels would cause more problems than it would solve by causing over flow from the bowls in level terrain...not necessarily a good thing on a hot engine even tho it runs thru a tube unless itis blown back onto the engine. Maybe other carbs have more baffling in the bowls for your style

 

2 items I would check.

1- you say you have your needle clip set on the lowest posistion, WHY? Having it set in the 3rd or 4th position is usually the best, as far as I have seen and the tuning I have done. (Try it)
Running the clip in the lowest position is surely going to make your Rap run like ****. Trust me!

2- the floats in the stock Rap carbs have been known to come from the dealers not set to specification. (Check it) If you need the spec's, well here ya go.

* Float height specification should be 13mm
Measurement and adjustment steps: Hold the carbs upside down, measure the distance from the mating surface of the float chamber (gasket removed) to the top of the float. Adjustments are made by bending the float tang on the float (small little metal flap in the middle of the float).


Regarding the fuel sloshing around, yes, others have had this problem, but not to the extent you are currently experiencing.

&quot;My advise&quot;, try the top 2 and let us know what you find. If you haven't purchased a shop manual and plan to work on your Rap, you need the manual.




Swy

 

swytak has some good ideas.
However you don't need to remove the carbs to check the floats. Yamaha has a tool that is a rubber hose with a graduated clear plastic tube on it. You attach it to the drain, open the drain up &amp; hold the clear tube next to the carb &amp; you can see the fuel highth They shouldn't be too expensive..

 

I had the same problem on my 02 Raptor. The floats were allowing to much gas in the bowls and causing the bike to flood. I even had gas in the airbox going up hills because the carbs/floats were so far out of adjustment from the factory. Once adjusted to 13mm the bike has ran perfect on all terrain and conditions.