I bought a 2000 sportsman 500 RSE with a K&N filter and IDS2 exhaust. The quad jetting difinately feels wrong and its very sluggish and running blubbery. Can any of you tell me what the correct jetting should be for this setup ? I ride it in 4000 ft. altitude.

Thanks in advance,
Trakman1[img]i/expressions/face-icon-small-confused.gif[/img]

 

I ride my 500 with stock jets at 6,000 to 9,000 feet, and it runs fine. The SP500 is supposed to come from the factory jetted for 0-6,000 feet.

Your mods should be allowing more air to flow through the engine, and that would normally require a richer jet to feed that extra air. But I would think that your 4,000 altitude would compensate for the mods, and bring it back in line. If it's backfiring when you let off the gas, it's probably too lean. You can take your plug out and inspect it. If it's blackened and fouled, then it's too rich.

This may sound stupid, but it's worth checking. Could the choke be stuck on?