on my 400 xplorer with the hpd pipe they sent 250 and 260 mains and a 30 pilot jet .said i needed to lean it down some on the bottom with the 30//my stock one is a 35.i run the 260 main.i had this combo on before back in the summer but it is starting to cool down here alotso i left my stock pilot jet in so it would be richer but it has a noticable lag out of the hole that it didnt have when i run with the 30.should i put the 30 back in?i dont want to burn a piston down.

 

Not sure if they are still doing this but Dynojet in Las Vegas ofering the following:
If you live in or near Las Vegas, Nevada, and are willing to leave Dynojet your ATV for a few days, we will use it to develop ATV jet kits and subsequently install the kit for FREE!

All we ask is that your ATV have all stock drivetrain components and represent one of the following models:

POLARIS:
500 Scrambler
500 Sportsman EBS
335 Sportsman EBS
425 Magnum 4x4
425 Magnum 2x4





Dynojet site

 

don't have an answer to your question.............what year model xplorer do you have, and what pipe did you get from hpd?

 

i have a 99 400 xplorer and i got the hpd pipe from ritter.

 

Put the 30 pilot jet back in and put in a larger main jet. When the cold weather hits, all you really need to change is your main. Try the next size or two higher than what you are running now. Keep an eye on your plug to make sure you are not running lean!!! Good luck!!click here to see the "Denny" machines!

 

Just a little info. The pilot jet circuit looses adjustment effect once you go past 2.5 to 3 turns out. Before you change back. Gradually back out the pilot screw (1/4 turn at a time) check to see if you can obtain an acceptable throttle response before you get to the 3 turn out status. Of course keep an eye on the plug. Tis better to error on the side of richness.......hmmmm a good moto in life!!! The $90 for an EGT gauge and probe is the best money you can spend on your quad.

Good Luck,
KT