I recently added a Pro Design kit with a K&N filter (lid is off) and am having a loss of power. I can place a thick rag over the filter and it runs great so I figure I am getting too much air now and running lean. I have reviewed the numerous posts on this forum and think I can adjust the mixture screw to solve my problem. Does turning the mixture screw out further (3 turns instead of 2) result in a richer or leaner mixture? Also, I have never worked on a carb before, but since my local dealer wants $100 to adjust I am giving it a whirl. So what exactly do these mixture screws look like?

 

If im not mistaken u need to bump up ur main jet a bit and the air fuel mixture screw is on teh bottom of the carb

 

You need bigger main jets. I would suggest getting sizes 155-175 and play around with them till you get it right. They are only about 3 bucks each. To start I would try 165 and a 170 This is assuming you are around sea level.

You can email me and I will send you a link to a sight that will show you exactly how to do it with pictures. nocando@iskijay.com

Nocando

 

With no lid and a slip on you need to increase the main jet sizes and also turn the mix screws out to fatten the mixture. You may need to adjust the needle clip position as well. Do a search and you will find literally hundreds of topics that can explain what you need to do.

 

I am running 165s now that were installed after the WB pipe was installed (Yamaha charged me $125 to do this). I was hoping that adjusting the mixture screw would provide enough adjustment to get it running good again. If that doesn't provide enough of an adjustment, would raising/lowering the needle clip also work? The bike runs fine at 1/2 throttle or less, but really struggles over 1/2 throttle. Any insight would be greatly appreciated.

 

I sent you a word document with instructions and pictures. I would try a 170-175 maybe. Each carb has a different size.

Nocando

 

From what you have said, it sounds like you are running 165 jets in both carbs. Thats a no no with the raptor. Your left jet should be staggered 5 from the right carb. Regardless, you shouldnt have to go much fatter with a slip on pipe. I had a full CT pipe and K&N w/ outerwear w/o lid and ran 170/175. I had a 25 needle and was too rich most of the time. Good luck

 

I believe it is actually a 160/165, the Yamaha guy said it as I was dropping it off. I will try the 170/175 combination and see how that works. Thanks to all who responded, especially to RaptorRider who sent a kicka$$ step by step document. Another stupid question. Which carb takes the bigger jet? And is the GYTR brand the best route to go?

 

The right carb gets the bigger jet. Gytr is the same as mikuni. They are about 3 dollars no matter where you get them or what kind you get. Just dont mix any DynoJet jets into the mix or you will be all screwed up.

 

I reread the document RaptorRider sent and the smaller jet goes in the carb with the idle adjustment. Any comments on brands of jets would be appreciated.