# jetting help



## mississippimud3 (Mar 25, 2009)

My buddy is having a very hard time getting his jet kit right on. He has a 2 inch snorkel, and it when the jet kit installed he is running fine, but after a while the spark plug still foul out. It is a very black sooty color. Anybody have any suggestions. It's a 98 Polaris Sportsman 500.


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## rubiconrider (Aug 26, 2009)

well if its fouling its rich. is it dying out at all during some part of your throttle opening? 

this is how your carb works:
idle: idle mixture screw. (not your idle position screw) this is the screw that you have to turn all the way in and count the turns out
1/8-1/4: pilot jet
1/4-3/4: needle. this is the long needle that goes down into your main jet and allows more fuel to flow through the main jet as you open the throttle
3/4-WOT: main jet. once your needle is out of your main jet it is the only thing that controls fuel flow.

so you just gotta figure out where your getting to much fuel and correct it by adjusting your idle screw, dropping your needle or putting a leaner main jet or pilot jet in.


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## Guarino113 (Oct 3, 2009)

sounds like its too rich. im not an expert but he might need to go down in jet sizes. talk to bootlegger on here. he helped me with mine and he knows what hes talking bout.


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## Bootlegger (Dec 18, 2008)

It running too rich....Just drop down one size jet and go from there.


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## Bootlegger (Dec 18, 2008)

I replied in your other thread...

He is running rich. Tell him to go down one jet size and put a new plug in it and go from there...ride it around for about 20 minutes at all throttle positions. LET THE MOTOR COOL....then pull the plug and look at it. That is if its running good...If not let me know what throttle position its bad at and I will help you from there...Feel free to PM me with anything you may need along the way.


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## mississippimud3 (Mar 25, 2009)

Ok a new problem has arisen. The bike was running yesterday but was still not perfectly tuned, and when he went to crank it today it started acting really funny. It would crank and idle perfectly, but as soon as you give it gas it starts making a knocking sound in motor and chokes down until it dies. But again it will fire right back... Can't figure out what is going on.


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## Bootlegger (Dec 18, 2008)

I don't think that is his Jetting...


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