2-Stroke - Spark Plug & Ignition Coil Testing

The information contained in our websites is designed as a guide only, for assisting Repair Professionals. By using our information you are agreeing to our T&Cs.

This procedure will guide you through testing your Spark Plug and Ignition Coil.

1 – Turn the on/off switch to the on position and make sure the fuel is also turned on.

2 – Pull the recoil, to turn the engine, two or three times.

3 – Remove the cap of the Ignition Coil from the top of the Spark Plug.

4 – Remove the Spark Plug.

5 – Check the Spark Plug tip is getting wet with fuel. If not, there is a problem in your fuel system (tank, carb, filter, etc). See here for more details.

For the following steps, turn the fuel off so that the engine isn’t flooded whilst testing. Failure to do this will fill the crankcase with petrol.

6 – Test the Spark Plug to be sure it is firing correctly. This can be done with a Spark Plug tester or with a multimeter. To test with a multimeter, set your meter at Ohms (10 or 20k) and attach the Red wire to the top of the Spark Plug where you removed the cap. Next, touch the Black wire from the meter to the Spark Plug Electrode (the needle that sits under the metal that curves around the other end of the Spark Plug). A faulty Spark Plug will give a very low reading (0-0.05). Replace if faulty. 

7 – If the Spark Plug is working correctly, re-attach it to the Ignition Coil Cap. Hold the end of the Spark Plug tip to a metal section of the engine, and turn over the engine (you might need a friend to help). If all is working correctly, you should see a strong spark.

8 – Set the multimeter to resistance and with the negative probe, touch one of the tab connectors, put the positive probe to the inside of the Spark Plug Cap. Ideally, you should get 1.8-1.9 K-Ohms.

9 – If the reading isn’t correct, the Ignition Coil needs to be replaced. If the Ignition Coil passes the test, the problem is with one of the other parts of the ignition system.  Please contact us for a tailored testing guide.

Spanner Driver QUESTION

Did this fix it?

Spanner Driver Answer

Yes, help me find Parts.

Spanner Driver Answer

No, I need more advice. Let’s try the next thing.