2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 29Get this manual
MAINTENANCE Oil Pump Priming Procedure (Sportsman 400 H.O
NOTE: This priming procedure must be performed whenever the oil hose connection between the oil tank and pump inlet has been disconnected1Clamp or pinch off vent hose approximately 2" from oil tank to avoid the end of oil tank vent fitting, and before the vent line's pressure relief slit
Engine Breather Filter (Sportsman 300)
The engine breather filter is located in front of the breather hose attachment location inside the air boxClean foam filter during air filter serviceReplace as neededBreather Filter
Engine Breather Filter (Sportsman 400 H.O
23Run engine for 10-20 secondsRemove the clamp from the vent hoseThe oil pump will now be properly primed and ready for field operationThe in-line filter is similar in appearance to fuel filter, and is visible on the left side of the vehicle (A)Follow breather line out of the side of the air box and locate filterBlow through gently in direction of arrow on filter to check for cloggingReplace as neededA