2001 Polaris Sportsman 400-500 DUSE and H.O. Service Manual, Page 62Get this manual
MAINTENANCE
EXHAUST PIPE
The exhaust pipe must be periodically purged of accumulated carbon as follows: 1Remove the clean out plugs located on the bottom of the muffler as shown at right2Place the transmission in neutral and start the enginePurge accumulated carbon from the system by momentarily revving the engine several times3If some carbon is expelled, cover the exhaust outlet and rap on the pipe around the clean out plugs while revving the engine several more times4If particles are still suspected to be in the muffler, 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 wheelsMake sure the machine is in neutral and repeat steps and 3WARNING: SEE BELOW5If particles are still suspected to be in the muffler, drive the machine onto the incline so the front of the machine is one foot higher than the rearSet the parking brake and block the wheelsMake sure the machine is in neutral and repeat steps and 3WARNING: SEE BELOW6Repeat steps through until no more particles are expelled when the engine is revved7Stop the engine and allow the arrestor to cool8Reinstall the clean out plugsClean Out Plug