2001 Polaris SLH, Virage PWC Factory Service Manual, Page 128Get this manual
CarburetionExhaust Carburetor Pop-Off Valve Testing
If operating pop off pressure is too highthe amount of fuel available to the engine will be reduced, causing lean condition High pop off pressure may be caused byRestricted fuel inlet passage Inlet needle stuck in seat Corrosion on lever arm, lever arm pinandor return spring Incorrect lever arm return spring (Use only genuine Polaris parts) Fuel return line orifice missing
Testing Needle and Seat Pop Off Pressure
Attach pump to fuel, inlet
Individual
Pressure test each carburetor individuallyTo provide accurate readings remove the regulator diaphragm and its cover before testingWet the needle with WD40 TM or similar substanceNOTE: Do not use gasoline due to the hazard of fire Protect your eyes from the spray when the needle valve "pops off"
Remove the fuel lines connecting the carburetorsAttach the Mity Vac 1M to the fuel inlet fitting of the carburetor to be testedPlug the fuel return outlet of the carburetor to be tested Pressurize the carburetor with the pump until the needle valve pops offPump slowly and note the pressure when the valve opensTest the valve at least three times to ensure an accurate reading Be sure to keep the needle valve wetNOTE: The reason for wetting the needle valve is to duplicate actual conditions during operation When the engine is runningthe needle valve has fuel running through to wet it and engine vibrations to help the needle obtain good seal