Symptoms of a bad fuel solenoid on a riding mower are very similar to other issues that pop up in your riding mower. For example, a failing fuel pump, blocked fuel filter, or even a faulty choke all share the same symptoms as a bad fuel solenoid. So, knowing and understanding the symptoms in more detail will help you get a head start on your diagnosis. Let’s go over 4 symptoms of a bad fuel solenoid on a riding mower and how to confirm your diagnosis.
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How Tell Mower Fuel Solenoid is Faulty
The purpose of a fuel solenoid is to stop and start the flow of fuel. Once a solenoid malfunctions, it can no longer control the flow of fuel as needed by the lawn mower. When there’s a problem with your mower’s fuel solenoid, you’ll experience problems with cold starting, engine stalling, poor idling, and difficulty with acceleration.
4 Symptoms of a Bad Fuel Solenoid
Difficulty Cold Starting the Engine
Cold starting an engine can sometimes be troublesome, especially if you have a bad solenoid. If the solenoid is stuck in the off position, you won’t be able to get any fuel to the carburetor. If the solenoid is jammed partially open, you’ll get some fuel but not enough to start your engine. If you manage to get the mower started, try turning it off and back on again. If you face the same difficulty re-starting the engine, you could be dealing with a bad cut-off solenoid.
Repeated Stalling
Your engine will inevitably stall if it is fuel starved. Defective solenoids can work intermittently and don’t always fail in the off position. They can switch between on and off. You are more than likely dealing with a bad solenoid if you find that your mower stalls for no apparent reason.
Poor Idling
If your lawn mower has difficulty idling after warming up for a minute or two, then your lawn mower likely has a bad solenoid. During idling, the mower uses less fuel and will manage to cope with the reduced flow of fuel. The mower may be able to keep running depending on how the solenoid responds, but you’ll definitely notice a problem.
Trouble with Acceleration
It is easy to tell the solenoid is faulty when you increase the acceleration and load on the engine. The mower will struggle to accelerate because the bad solenoid creates a blockage in the fuel pump, limiting the amount of fuel delivered to the engine. You’ll notice an improvement if you reduce the revs since less fuel is required.
An Easy Way to Test Bad Fuel Solenoid on a Riding Mower
If you have noticed the symptoms of a bad fuel solenoid on a riding mower, you’ll want to confirm that your diagnosis is correct. Here are two tests you can do to determine if your mower has a faulty solenoid.
Energize the Solenoid ON the Riding Mower
When a solenoid has no power, it is unenergized and will remain in the OFF position. Once you switch on the ignition, it will energize and move to the ON position. Start by locating the solenoid on the engine and switch the ignition to ON. Once the solenoid receives power, it will energize and move its internal pin. If you listen carefully, you will hear a click as the solenoid moves. Alternatively, place your hand on the solenoid and switch on the ignition. Now you’ll be able to feel if the solenoid is working or not.
Energize the Solenoid OFF the Riding Mower
As we covered earlier, solenoids can go bad in different ways. For example, yours may pass the test on the mower, but an incomplete movement of the pin needs further investigation.Â
How to Remove the Solenoid
- Switch off the mower’s fuelÂ
- Remove the electrical connection to the solenoid
- Use a wrench to loosen off the solenoid
- Catch leaking fuel with a small container
- Completely remove the solenoid from the mower’s carburetor
How to Test the Solenoid
- Work the solenoid mechanism by pulling and pushing the center pin
- Look for any restriction that could be causing a problem
How to Energize the Solenoid
- Grab a few lengths of electrical wireÂ
- Connect the solenoid directly to the mower’s battery
There is no need to worry about polarity since a solenoid will work either way. Once you energize the solenoid, the pin should move. If the pin doesn’t move or has trouble, you have a bad fuel solenoid on your riding mower that needs replacing.
