2007 Polaris Two Stroke Snowmobile Workshop Repair manual, Page 88Get this manual
FUEL DELIVERY Fuel Screw
The fuel screw controls the fuel mixture from idle to low speedsThe tapered tip of the fuel screw projects into the passage leading to the by pass out letBy turning the screw in or out, the cross sectional area of the air passage is varied, in turn varying the fuel screw varies the amount of airfuelalways use the lowest elevation and temperature that is likely to be encountered
CAUTION
A Main Jet that is too small will cause lean operation condition and may cause serious engine damageJet the carburetors carefully for elevation and temperature according to the jetting charts in the, Specifications Chapter of this manual or the models Owner's Manual Supplements
Main Jet
When the throttle opening becomes greater and the area between the needle jet and jet needle increases, fuel flow is metered by the main jetThe number on the jet indicates the amount of fuel which will pass through it in one minute under controlled conditionsLarger numbers give greater flow, resulting in richer mixtureMain jets are screwed directly into the needle jet base