2004 Yamaha Motorsports Bruin 350 Auto. 4x4 Owners Manual - Page 128
2004 Yamaha Motorsports Bruin 350 Auto. 4x4 Manual
Page 128 highlights
7. Apply Yamaha foam air filter oil or other quality foam air filter oil to the air filter element. If foam air filter oil is not available, engine oil may be used. NOTE: The air filter element should be wet but not dripping. _ _ 8. Pull the air filter element over its frame. 9. Install the air filter element assembly. 10. Install the air filter case cover by hooking the holders. 11. Install the seat. NOTE: The air filter element should be cleaned every 20-40 hours. It should be cleaned and lubricated more often if the machine is operated in extremely dusty areas. Each time the air filter element maintenance is performed, check the air inlet to the filter case for obstructions. Check the air filter case rubber joint to the carburetor and manifold fittings for an airtight seal. Tighten all fittings securely to avoid the possibility of unfiltered air entering the engine. _ _ CAUTION: _ Never operate the engine with the air filter element removed. This will allow unfiltered air to enter, 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. _ 8-21