It's pretty obvious how lean the pilot jets are on the Raptor, especially if you have opened up the pipe and airbox. Who knows (by trying) how much richer to go up? #22.5 is stock...since I don't like going into the carbs multiple times, I'm wondering how much richer you can go without overdoing it. I'm not sure #25 pilots are rich enough. Anyone got any info on this? Also, what is the maximum sizeup on the main jets, without going too rich? Anyone tried more than one needle jet clip position richer? Thanks for the help.

 

OK...Somebody's got to have some info on this!! Anyone?

 

I would like to know the answer also Scott. Surely someone has been thru this. Scott...do you know if both carbs require the same pilot jet size?

 

In stock form, both carbs use the same size pilot jet(22.5 is stock), both have the needle clip in the same position (3rd slot from the bottom) the left carb has a 140 main, and the right side has a 145 main. There is a power jet in the left carb for mid range and acceleration. It is a 95 stock. I sized it and it was not exactly a 95 so I reamed it with a jet ream tool to a 95. I changed to 25 pilots, a 142.5 main in the left, 147.5 in the right, lowered the needle clips one position, and removed the pipe baffle. I ride at approx. 3500ft and the plug has a very light brown color. I am close to correct jetting at this altitude but I'm sure it is lean at sea level. I will probably go up one more size on the mains (145 left side, 150 right side. I have not made any air box mods yet.

 

Where do you get a jet ream tool? How do you determine what a #95 is? Is it possible to buy bigger power jets?

 

The jet ream is part of a kit I purchased many years ago. It consists of several sizes of very fine pitched jet reams and jet size gauges. It is a very specialized (i.e. hard to find and expensive) tool. I paid $150.00 for it 20 years ago. The #95 power jet is the same style as the main (i.e. Mikuni small round). I only very slightly reamed it to make it an actual 95. I seriously doubt it was enough to have any effect. I am going to hold off changing that jet for now.
Sudco has (had?) all the different sizes of the small round mains in stock when I went there.

 

I presently have 25 pilots in both carbs. My only mod is the removal of the pipe baffle. My air /fuel screws were both set at 2.5 turns out from the factory so I am setting them the same. Right now they are both at 2 turns out. Turning them out makes the idle circuit richer, in makes it leaner. I didn't want to make a huge initial change so I compensated for the bigger pilots by making the air/fuel mixture leaner. The bike starts and idles without the choke almost immediately and has good throttle response so that circuit is pretty close to being right. I can't say yet what is too rich. I needed more time to try other sizes but I was going riding for several days and that's as far as I got. I may try to see what's too rich but it's pretty close right now.

 

Are you sure turning the pilot air screw out is richer - this is opposite to an aftermarket mikuni single carb I have?

 

Mikuni told me that what the air/fuel screw adjusts depends on what side of the carb slide it is on . If it is on the side closest to the engine it adjusts fuel. If it is on the side furthest away from the engine it adjusts air. The air/fuel screws on the Raptor are on the side closest to the engine. Turning them in cuts off fuel making the mixture leaner. Out makes it richer.

 

Thanks for all the good info, Maynard! Keep it coming as you find out more! It's refreshing to actually get some intelligent, well-informed information!