2003 Polaris Deep Snow Snowmobiles Service Manual, Page 140Get this manual
FUEL SYSTEMCARBURETION The jet needle and needle jet have the most effect between 38 and 34 throttle openingSome mixture adjustment can be accomplished by changing the location of the "E" clip on the needleMoving the clip down raises the needle in the jet passage and richens the mixtureMoving the clip up lowers the needle in the jet passage and leans the mixtureLetter and number codes are stamped into the needle and the jet indicating sizes and tapers (taper of needles only) of each
JET NEEDLE
Jet NeedleNeedle JetFig1
The jet needle tapers off at one end and the clearance between the jet needle and the needle jet increases as the throttle valve opening gets widerThe airfuel mixture ratio is controlled by the height of the "E" ring inserted into one of the five slots provided in the head of the jet needleThe chart at right shows the variation of fuel flow based on the height of the "E" ringNEEDLE JET