I have a 99 Warrior with a White Brothers E-Series exhaust. For Christmas I got a K&N Power Jet Kit. It came with the proper jets, KN Air Filter, Precharger and Recharger kit. Since the Warrior stock has a 145 main jet I put in the 150 main jet supplied with the kit. The machine runs great as long as you do punch right off idle to full throttle then it acts like it wants to cut off. Has anyone else had this problem? And what can I do to cure it?

 

Drop the main jet one size you are too rich. Or you could open your air box up or drill holes in the lid.

 

Well see at first the instructions said to put in a 136 main jet but that really was bad. So I went to my Yamaha dealer and explained the situation. They told to put in the 150 and it should fix it. Does anyone else have the modifications?

 

What altitude are you riding at?

 

It's pretty cheesy for them to print the "correct" jet size in the manual. They should have stated that altitude, temperature, exhaust flow, and other things determine correct jetting. You've got to learn to read the plug. Two sizes up may have been perfect for THEIR test vehicle, but who knows the circumstances of their test?

 

99WarMachine I am at an altitude 0-3000 ft above sea level I am not sure for exact altitude. Does your Warrior run fine with a 155? Maybe that is what mine needs.

 

BadWarrior, you and I ride at the same altitude. So far my 155 does great at 2500'. I took my airbox off one day, and when I put the drop-in style K&N filter, I could see through the intake hole, that a good portion of it was blocked off, because the foam/rubber gasket wouldn't fit properly, and just got mashed up. This how it was when first put the 155 in, and I noticed It would cut out at high RPM's because it was running too rich. A while later, I machined a mounting flange so I could install a clamp-on style K&N. This way, the carb was free to suck in as much air as possible, now that I didn't have a mashed up gasket blocking the intake. I also completely removed the airbox lid.

So to sum it all up, I needed to open my intake up as much as possible, to use a 155 main jet effectively.

Depending on how muddy you get, you may not want to remove the airbox lid, but if that's the case, I don't think you'd be able to use a 155. Otherwise, try it out.