I have a K&N Filter, Jet Kit, FMF Pipe and I want to run with the air box off. I did for a little bit last weekend but then I noticed that I had actually lost power. I ordered a 150 through 160 pack of jets but I was wondering what size I should go. Thanks

 

I am confused. You say you have the Jet Kit for your bike but you are talking about ordering jets?????
Depending on the altitude you ride at, you probably want to be running a 165 or 170 main jet. You also want the clip on the needle on the fourth groove counting from the top down.

 

? for you slyder what does moving the needle up
or down do.

 

OK, first some background information on carburetor jetting. There are three metering circuits, the pilot, the needle and seat, and the main. The pilot jet and air screw control the mixture from idle to 1/4 throttle. The needle and seat control the mixture from 1/4 to 3/4 throttle. The main controls the mixture from 3/4 to full throttle. Obviously, there is some overlap, but this gives you the general idea.

The object of moving the clip on the needle is to adjust the mixture in the middle of your throttle range. By moving the clip lower, you raise the needle farther out of its seat. The needle is tapered; therefore, raising it causes the narrow portion to rise out of the seat sooner, which effectively richens the mixture. Raising the clip (which lowers the needle) causes the opposite effect.