2002 Yamaha Motorsports Big Bear 400 4x4 Owners Manual - Page 124
2002 Yamaha Motorsports Big Bear 400 4x4 Manual
Page 124 highlights
EBU00283 EBU00286 Front axle boots Check the protective boots for holes or tears. If any damage is found, have them replaced by a Yamaha dealer. 1. Boot (× 2) Spark plug inspection The spark plug is an important engine component and is easy to inspect. The condition of the spark plug can indicate the condition of the engine. For example, a very white center electrode porcelain color could indicate an intake air leak or carburetion problem for that cylinder. Do not attempt to diagnose such problems yourself. Instead, take the machine to a Yamaha dealer. You should periodically remove and inspect the spark plug because heat and deposits will cause the spark plug to slowly break down and erode. If electrode erosion becomes excessive, you should replace the spark plug with one of the proper type. Standard spark plug: DR8EA (NGK) 1. Boot (× 2) 8-13