An ignition system in a small engine produces and delivers the high-voltage spark that ignites the fuel-air mixture to cause the combustion. Some small engines require a battery to supply electrical power and the ignition spark. Others develop the ignition spark using a magneto.
How do small engines get spark?
When you start your lawn mower or small engine, you turn the flywheel and its magnets pass the coil (or armature). This creates a spark. … Once the engine is running, the flywheel keeps rotating, the magnets keep passing the coil and the spark plug keep firing based on a specific timing.
How does the ignition system work on a lawn mower?
How Do Ignition Systems Work in Small Engines & Lawn Mowers? … The ignition system coordinates the timing so that the spark will ignite the air-fuel mixture in the combustion chamber just as it reaches maximum compression in each engine cycle- thus, maximizing the engine’s power.
How do you test an ignition module on a small engine?
Watch for a spark in the tester window as you pull the starter cord. To test the operation of both the ignition coil and the spark plug, connect the tester between the spark plug boot and the spark plug. Then start the engine and watch the tester window.
What causes loss of spark?
Loss of spark is caused by anything that prevents coil voltage from jumping the electrode gap at the end of the spark plug. This includes worn, fouled or damaged spark plugs, bad plug wires or a cracked distributor cap.
Why does my lawn mower have no spark?
If no spark appears, check for broken wires, shorts, grounds or a defective stop switch. Once you have confirmed that the stop switch is working, reconnect the spark plug lead. If your ignition start or push button start needs replacing, consult a Briggs & Stratton dealer near you.
How does a kill switch work on a small engine?
What Does A Kill Switch Do On a Petrol Lawnmower? is connected it stops the ignition coil sending any current to the spark plug, this, of course, means the lawnmower won’t start. In the UK a kill switch is fitted by law. This is so you can’t leave a lawnmower engine running while you are not near it.
What makes a lawn mower coil go bad?
The operating temperature of the engine gets to hot and burns the coil out. This is not real common on a small engine as usually the engine will shut down from heat before the coil will fail, but it is possible. Resistance problems. If the wrong spark plug is used, you can count on the coil failing.
How many ohms should a ignition coil have?
Most ignition coils should have a primary resistance falling somewhere between 0.4 and 2 ohms; however, refer to your manufacturer’s specifications for the correct reading. If a reading of zero is displayed, that signifies that the ignition coil has shorted internally in the primary windings and needs to be replaced.
How do I know if my small engine coil is bad?
Your mower may have a bad coil, especially if you cannot re-start your mower while it is still hot. If you have to wait for the mower to cool to start it, you should probably replace the ignition coil.
How do you know if your ignition control module is bad?
One of the first symptoms of a problem with the ignition module are engine performance issues. If the ignition module fails or has any problems it can lead to performance issues with the vehicle, such as misfires, hesitation, loss of power, and even reduced fuel economy.
How do I know if my ignition module is bad?
Signs of a Bad Ignition Module
- Acceleration Issues. The vehicle may shake, vibrate or jerk when the gas pedal is pressed. There may be hesitation or lack of power during increases in speed.
- Temperature Problems. A faulty ignition module can cause a vehicle to overheat. …
- No Power. The engine may turn over without starting.
How do you know if your spark is weak?
A good spark will be blue-white and will be plainly visible in daylight. If a good spark is present, the problem is probably not in the ignition system. Check the fuel system and/or stark timing. Weak sparks are orange or red and may be hard to see in daylight.
How do you check the power of an ignition coil?
Locate the positive or power wire attached to the engine coil. Check for power using a test light. If this wire has no power, then your ignition coil is not receiving current. You should check the wiring from your ignition switch to the coil for breaks in the wire and repair them.
Why must you recheck the ignition system?
It is therefore important to ensure that it is good condition, since even if your car does start and run, neglecting your ignition system may result in impaired performance, reduced fuel efficiency and an increase in noxious and unpleasant emissions.