How to Test an Ignition Coil for a Yamaha YFM 80

Save

Yamaha's YFM80 all-terrain vehicles were available in several variations throughout the years, many of which mimicked Yamaha's larger Raptor and Badger models. Despite their varying appearances, they were all built on top of the same frame and engine. A difficult-to-start ATV, or random misfiring, is usually a symptom of a failing ignition coil, which prevents the spark plug from receiving the electrical voltage needed to generate a healthy spark. While a commercial spark tester can be used to check that a spark is indeed being produced, the coil's internal windings must be tested with a multimeter to ensure that the spark is adequate to power the ATV.

Things You'll Need

  • Ratchet
  • Socket set
  • Multimeter
  • Park the ATV on a level work area. Remove the seat from the ATV, using the release lever under the rear of the seat.

  • Remove the front panel or grill from the front fender, using a ratchet. Remove the front fender mounting bolts, using a ratchet. Lift the fender off of the ATV. Unscrew the ignition switch lock nut from the right side of the front fender by hand, then push the ignition switch out of the fender.

  • Turn the fuel valve, located under the bottom-left corner of the fuel tank, to the "off" position. Unscrew the fuel tank mounting bolts using a ratchet. Lift the tank off of the ATV and pull the fuel hose off of the fuel valve outlet using pliers.

  • Grasp the spark plug cable cap, located on the left side of the engine cylinder, then pull the spark plug cable off of the spark plug. Follow the spark plug cable to the ignition coil, located along the ATV's frame rail. Unbolt the ignition coil, using a ratchet, then unplug the coil from the ATV's wiring harness.

  • Pull the cap off of the spark plug cable. Set a multimeter to a 1x resistance setting. Place the meter's red probe into the cap's spark plug receptacle and the black probe into the cable-end of the cap. The meter should indicate a resistance reading of 10k Ohms. Replace the spark plug cap if the resistance is greater than 10k Ohms.

  • Move the red probe to the ignition coil's wiring terminal and the black probe to the ignition coil's body. The meter should indicate a resistance reading of 1.4 to 1.8 Ohms. Replace the ignition coil if the resistance reading is greater than 1.8 Ohms.

  • Move the red probe to the ignition coil body and the black probe to the end of the spark plug cable. The meter should indicate a resistance reading of 5.3 to 7.9k Ohms. Replace the ignition coil if the resistance reading is greater than 7.9k Ohms.

  • Push the spark plug cable cap onto the end of the spark plug cable. Reinstall the ignition coil onto the ATV's frame. Push the spark plug cable cap onto the spark plug.

  • Reinstall the fuel tank onto the ATV, then push the fuel hose onto the fuel valve outlet. Reinstall the front fender, front grill and seat.

References

  • 2001 Yamaha YFM80P Supplemental Service Manual; Yamaha Motor Corporation
Promoted By Zergnet

Comments

Related Searches

Check It Out

How To Travel For Free With Reward Points

M
Is DIY in your DNA? Become part of our maker community.
Submit Your Work!