2010 Yamaha Motorsports Big Bear 400 4x4 IRS Owners Manual - Page 104

12. Install the seat. TIP The air filter element should be cleaned every 20- 40 hours. It should be cleaned more often if the ATV is operated in extremely dusty areas. Each time the air filter element maintenance is performed, check the air inlet of the air filter case for obstructions. Check the air filter case rubber joint to the carburetor fittings and the rubber joint manifold fittings for an air-tight seal. Tighten all fittings securely to avoid the possibility of unfiltered air entering the engine. EBU27081 8 10. Pull the sponge material over the air filter element. 11. Insert the air filter element assembly into the air filter case, and then install the air filter case cover by hooking the holders onto the air filter case. NOTICE: Make sure that the air filter element is properly seated in the air filter case. Never operate the engine with the air filter element removed. This will allow unfiltered air to enter the engine, causing rapid engine wear and possible engine damage. Additionally, operation without the air filter element will affect carburetor jetting with subsequent poor performance and possible engine overheating. [ECB00461] 8-23 Cleaning the spark arrester Be sure the exhaust pipe and muffler are cool before cleaning the spark arrester. 1. Remove the bolts.