How to Troubleshoot a Toro Push Mower With No Spark
- 1). Turn the ignition safety switch "on" and be sure that all attachments are disengaged and that the transmission is in neutral. Be sure all safety devices are all set in their operating positions so that the engine is not forced to stall. Try to start the engine. If it does not start, and you suspect an electrical issue, continue troubleshooting.
- 2). Adjust the spark plug wire by squeezing the end connector (the part that attaches to the spark plug tip) with pliers slightly, so that when it is attached to the spark plug it fits securely on the end of the spark plug. It should not wiggle or be loose. Try to start the engine again. If it does not start, continue troubleshooting.
- 3). Check for an ignition spark presence by first removing the spark plug with a spark plug wrench, then grounding (allowing to touch) the hexagonal metal part of the spark plug with a bare metal part of the engine (such as the metal cooling fins just adjacent to the spark plug).
- 4). Remove any spilled gasoline or other flammable debris that is nearby, then quickly rotate the engine by pulling the starter rope several times (or using the electric starter). Look closely while the engine rotates, and you should see a small blue spark arc across the spark plug gap (portion of the tip of the spark plug between the electrode and the center piece of the spark plug. If you have a visible blue spark as the engine rotates, you have a sufficient spark to start the engine. If you see no spark, continue troubleshooting.
- 5). Repeat the previous step (number 4 above), with a drop cloth draped over the mower. If no drop cloth is available, any dark location (garage) or the same test done after sunset will suffice. The added darkness should enable you to verify that a blue spark is being delivered within the spark plug. If you see a bright blue spark, the problem you are experiencing is not a spark (ignition) related issue. If you still see no spark, continue troubleshooting.
- 6). Install a new spark plug if the spark is yellow and weak in brightness, or there is no spark visible at all. Be sure to set the new plug gap to the proper specification (usually 0.030 inch on a Toro) and check for bright spark again (with the spark plug still removed from the spark plug hole). If you do see a spark after the new plug was connected to the spark plug wire, install the new plug and try to start the machine. If you still see no spark, the problem exceeds the scope of a routine maintenance repair.
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