How to Troubleshoot a Yamaha Timberwolf

by Brianna Collins

Discontinued in 2000, the Yamaha Timberwolf was a utility ATV that Yamaha manufactured to be capable of heavy-duty work and trail riding. In its final year, the quad featured a 229.6 cc engine that took unleaded fuel as a main fuel source. The ATV also featured NGK D7EA spark plugs, a capacitive discharge ignition system, and a 12 volt, 12 ampere-hour battery. Problems with any of these systems could result in trouble with starting and running the 2000 Timberwolf, and Yamaha recommended a number of troubleshooting steps to deal with these simple repairs.


If there is no fuel, refill with unleaded gasoline and restart the engine.

If there is some fuel, turn the fuel cock to "RES" and restart the engine. If it will not start, proceed to the next step.

If there is an adequate amount of fuel, turn the fuel cock off and remove the fuel pipe. Check the fuel flow. If there is no fuel, it is likely that the fuel cock is clogged. Clean the fuel cock and restart the engine.


The ignition must be dry before troubleshooting. If it is wet, wipe it clean with a dry cloth.

Once the ignition is dry, ensure that the spark plug cap is attached and connected to the chassis to ensure proper grounding. Use the electric starter. If the spark is good, then there is no problem with the ignition system.

If the spark is weak, tighten the spark plug gap to between 0.03 and 0.04 inches. Try the starter again. If it is still weak, replace the spark plugs.

If there is no spark, there is a problem with the ignition system, and the 2000 Timberwolf should be taken to a Yamaha dealer for inspection.


Using the electric starter, check to see if there is compression.

If there is compression, then there is no problem with this system.

If there is no compression, this may be the cause of problems. Take the quad to a dealer and have them inspect the compression system.


Use the engine starter and observe how quickly the engine turns over. If it turns over quickly, the battery is working properly.

If the engine turns over slowly, check battery fluid, recharge the battery and ensure that all connections are tight. Try starting the quad again.

If the engine still turns over slowly, replace the battery.


  • check If all of these systems are working properly, Yamaha recommends that owners take the quad to a qualified dealer for more serious repairs. The manufacturer cautions against attempting these repairs without the proper tools and training.


  • close Do not smoke or work near an open flame when inspecting the fuel line, as gasoline fumes can ignite and cause an explosion.
  • close Exercise caution when inspecting or replacing the battery, as battery fluid contains poisonous sulfuric acid and also produces explosive gases. Avoid direct contact with skin, keep batteries away from children and always wear eye protection while working with batteries.

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About the Author

Brianna has been writing professionally since 2009. She has a Bachelor of Fine Arts degree and is excited to be part of a community that contributes to the free sharing of information and ideas.

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  • photo_camera old spark plugs image by Rog999 from