The stator coil generates the power for the spark plug and other accessories on small engines Without a stator there would be no spark at all, meaning the engine won't run. While a stator is dying, it can produce a weak spark, causing the engine to miss or run poorly. Symptoms are often worsened as the engine warms up.

What would cause a weak spark?

If the spark is still weak after replacing the whole ignition system, then the normal size wiring or connector to the coil may be corroded or damaged somehow. The other real longshot is that the grounding strap between the engine/trans, body, and negative battery terminal is corroded/worn/damaged.

How do I know if my stator is bad?

Insert each probe into a stator socket. You should read around 0.2 to 0.5 ohms. If you show an open circuit with the “Open” or infinity reading or have higher resistance, then the stator is bad and you must replace it. If these tests all produce positive results, then the stator itself is good.

Can a bad rectifier cause no spark?

The regulator/ rectifier is a voltage regulator that keeps the battery supplied with a steady 13.4 dc volts no matter what the stator is putting out, which is AC volts that varies with engine RPM. A bad regulator/ rectifier will result in a dead battery, and once the battery is competely dead you will not get a spark.

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.

WEAK OR NO SPARK? DOES IT NEED A NEW COIL? / OLD MECHANICS TRICK TO FIX A MAGNETO IGNITION SYSTEM

32 related questions found

What causes a weak spark at the spark plug?

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.

Can CDI cause weak spark?

Re: reasons for weak spark on CDI system? The COIL can give weak spark in spite of the spark being triggered by a CDI box. If you have an anemic yellowy spark from the plug then I would suggest to check that all of the connections are clean and tight.

Will a bad diode cause no spark?

If the negative diode on this phase shorts out to ground ( there are 2 diodes 1 positive, 1 negative) this can cause a no spark condition. Test the rectifier with a multimeter to see if there are any bad diodes.

What are the symptoms of a faulty regulator rectifier?

Probably, the most common symptom associated with a bad regulator is flickering, dimming, or pulsing lights. To be more specific, you may notice that the vehicle's: Headlights fluctuate between bright and dim, without you doing anything. High beam isn't working as expected.

Will a motorcycle run with a bad rectifier?

A rectifier converts alternating current (AC) to direct current (DC) to charge the battery. ... Since motorcycles require battery power to start them up, a bad rectifier will eventually result in the motorcycle not able to start.

What happens when stator goes bad?

The most obvious symptoms of a bad motorcycle stator include no spark, weak spark, or intermittent spark (also known as misfiring). Hard starts and a poorly running engine can also be clues that your stator needs to be rebuilt or replaced.

What causes a stator to fail?

When a stator fails, it is largely due to the degradation or aging of its insulation through external occurrences and materials being introduced into its system.

Will a bad rectifier damage a stator?

If the rectifier/regulator failure results in too low resistance the stator probably will burn (too much current). If I disconnect the rectifier/regulator the voltage will go up, but how high? Is it possible that the voltage will go high enough to destroy the isolation?

What does a weak spark mean?

An engine is considered to misfire when there is not enough electrical energy going to the spark plug to keep it arcing or there is a path- way in the engine for the energy to take that bypasses the plug's electrodes. Electricity is lazy.

Can a bad ground cause weak spark?

Actually, the operation of the points is what causes the coil to generate the spark, So if they are not right, or grounded improperly you will get a weak or no spark.

What are the symptoms of a weak ignition coil?

If your car is experiencing any of the problems listed below, you may have a faulty ignition coil on your hands:

• Engine misfires.
• Rough idle.
• A decrease in car power, especially in acceleration.
• Poor fuel economy.
• Difficulty starting the engine.
• Check engine light is on.
• Exhaust backfiring.
• Increased hydrocarbon emissions.

What happens when voltage regulator goes bad?

A damaged or failed voltage regulator can rapidly diminish the alternator's ability to cycle power from the battery. This may cause the vehicle to experience dimming or pulsating external systems, such as headlights and dashboard elements.

What is regulator rectifier?

A regulator rectifier is a standard component of this circuitry. ... In any case, the regulator rectifier converts the AC power into DC power, then regulates the DC power to ensure that the power doesn't go over around 14.5 volts. At this point, the DC voltage routes to the battery of the bike.

Can a voltage regulator cause no start?

A bad voltage regulator may cause it to simply not work or behave erratically. You're not likely to be able to start the car at all, but even if you could, it wouldn't be wise to do so without knowing how fast you're driving, how much fuel you have left, and other critical info.

Can a weak spark cause a misfire?

One of the most common cylinder misfires causes originating from the ignition system is a weak spark coming from the spark plugs. In this case, the weak spark can cause the engine misfire, leading to jerking while accelerating.

What causes a weak spark on an ATV?

The most common reason an ATV is getting no spark is a bad spark plug, either the wrong plug all together or just not gapped correctly. Or the spark plug just went bad, that happens quite often and it's normal.

Can a bad condenser cause weak spark?

Weak spark is often the result of a bad condenser (and it's a cheap part to replace). If you see higher resistance here, then you need to clean and check the connections and the circuit path to ground through the points. Also check resistance between the distributor body and the engine block.

Can a coil pack be weak?

One of the earliest signs of determining a weak coil pack is engine misfires, also known as "hard starting." A misfiring engine will cause the car to sound choppy or shake, and can make it feel as if the vehicle is stalling.

Can ignition coil cause weak spark?

Of course, a faulty ignition coil will have a bad influence on the engine's performance. ... A weak spark is the first sign that the ignition coil may be failing. During acceleration, the air and fuel that is forced into the cylinders extinguish whatever spark there is, which causes the car to stall.