2007 Yamaha Motorsports Big Bear 400 4x4 IRS Owners Manual - Page 116

2. Start the engine and rev it up approximately twenty times while momentarily creating exhaust system back pressure by blocking the end of the muffler with a shop towel. 3. Stop the engine and allow the exhaust pipe to cool. 4. Install the purging bolt, and then tighten it to the specified torque. Tightening torque: Purging bolt: 10 Nm (1.0 m·kgf, 7.2 ft·lbf) EWB01920 HOW TO AVOID THE HAZARD When cleaning the spark arrester: Always let the exhaust system cool prior to touching exhaust components. Always wear eye protection, and make sure no one is behind the ATV. Never run the engine in an enclosed area. Make sure there are no combustible materials in the area. EBU23940 Adjusting the carburetor The carburetor should be checked and, if necessary, adjusted at the intervals specified in the periodic maintenance and lubrication chart. The carburetor is an important part of the engine and requires very sophisticated adjustment. Therefore, most carburetor adjustments should be left to a Yamaha dealer, who has the necessary professional knowledge and experience. The adjustment described in the following section, however, may be performed by the owner as part of routine maintenance. WARNING 8 POTENTIAL HAZARD Improperly purging the exhaust system. Hot exhaust system. WHAT CAN HAPPEN Could injure the eyes. Could cause burns. Could cause carbon monoxide poisoning, possibly leading to death. Could start a fire. 8-24