2008 Polaris ATV Sportsman 300 400 H.O. Service Manual, Page 33Get this manual
MAINTENANCE Exhaust Silencer Cleaning WARNING
Do not perform clean out immediately after the engine has been run, as the exhaust system becomes very hotSerious burns could result from contact with exhaust componentsTo reduce fire hazard, make sure that there are no combustible materials in the area when purging the spark arrestorWear eye protectionDo not stand behind or in front of the vehicle while purging the carbon from the spark arrestorNever run the engine in an enclosed area.Exhaust contains poisonous carbon monoxide gasDo not go under the machine while it is inclined.Set the hand brake and block the wheels to prevent roll backFailure to heed these warnings could result in serious personal injury or deathThe exhaust silencer must be periodically purged of accumulated carbon as follows: 1Remove the clean out plug located on the bottom of the silencer1 ft3If some carbon is expelled, cover the exhaust outlet and lightly tap on the silencer around the clean out plug with rubber mallet while revving the engine several more timesIf particles are still suspected to be in the silencer, back the machine onto an incline so the rear of the machine is one foot higher than the frontSet the parking brake and block the wheelsRepeat steps and 3SEE WARNING