Troubleshooting a Riding Lawn Mower That Won't Start

If your riding mower will not start (most of these tips are applicable to push mowers also):

1. Make sure you have fresh fuel; dirty or old fuel will not burn. Consider an octane boosting additive.
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2. Make sure the oil level is correct; too much or too little oil will prevent the mower from starting.
3. Most riding mowers start only when in neutral and when the blades are not engaged; make sure the trans is in neutral and the blades are not engaged. Engage the brake and/or clutch.
4. Ensure it's getting fuel to the carburetor by pulling the line at the closest inlet near the carburetor, then cranking; it should spurt fuel. Make sure if you put new fuel in the tank, that you purge the old fuel from the lines by this method.
5. If you are getting fuel, the carburetor may be dirty from fuel setting in the bowl for a long time; take the carburetor apart by removing the brass bolt from the bottom of the bowl, and cleaning the bottom parts with carburetor cleaner.
6. Make sure the seat switch engages when you sit squarely in the seat.
7. Wear safety glasses when you use pressurized air to clean dirt off of the entire engine; leaves, dirt, and other foreign particles may prevent the engine from breathing. Keep the top of the flywheel and the fins on the flywheel clean.
8. If the magneto(s) or the flywheel are rusty, you won't get spark; use emery cloth to sand the rust off of the flywheel and the magneto(s). You have to remove the magneto to clean the rust off. Get all the rust off; the flywheel needs to shine where it makes contact with the magneto(s).
9. Dead batteries are usually bad batteries. If the battery is dead, and does not charge, you probably have a bad alternator, or a bad battery.
10. Make sure you 'choke' the carburetor the first time you crank it. After some cranking, you may need to adjust the choke. Make sure the throttle is adjusted to the 'Start' position.
11. The air filter must be clean: If your carburetor is starving for air, the mower will not start. Clean the filter with soapy water and a soft brush. Hold the filter to a light, or the sun; you should be able to see light through the filter. Try starting without the filter, but do not operate the mower without the filter.
12. Grass build-up in the mower deck may prevent the mower from starting. Make sure to pull the spark plug when you tip the mower to bust the clogged grass away from the deck. Be aware that tipping the mower can cause oil to leak from the engine block into the cylinder, which will result in smoke from the muffler due to oil burning; it should just last a minute or less.

My riding mower will not start unless I charge the battery. Parts store says battery is good.

My rider won't start. I replaced the filter, plugs, and fuel pump. It's not getting gas. Any ideas? If I put gas directly into the carb it starts for a few seconds. The gas lines are clear.

The ignition switch won't start the engine for my 12 hp Ranch King riding mower.

Hi, I had checked the fluids before starting and I did a couple rounds. I had pause for a moment and had foot on the clutch and was idling on rabbit, I slow it down to middle and then let go of the clutch and then it stalled and it won't start again.

When I turn the key the B+G 12.5hp engine (lawn tractor) turns and then sticks. The starter is new. Is the next potential suspect battery or solenoid?

My brother has an old riding mower (90s I think) that won't start. He put in fresh gas, a new battery, and fresh oil, but the engine won't start. He says it's just making a click, the motor shakes, but nothing happens.

Scot S16/42 Riding Mower (Kohler engine) won't turn over. I have a good battery, new starter motor, new ignition switch, new starter solenoid, good gas, good spark plug, clean air filter, all safety switches work properly - all the normal stuff that prevents a riding mower gas engine from starting checked.

When I turn the key, (yes gas valve is turned on: throttle lever in start/chock position), nothing happens, no click...nothing.

If I use a jumper cable from the positive battery post and touch it to the positive electric starter motor (key in run position), the starter motor will turn over and start the engine.

Sometimes, when turning the key normally to start the engine, nothing happens until I start moving the throttle lever back and forth from the start/fast to normal run rpm's position simultaneously whilst holding the key in the start position - then starter motor turns over, and starts the engine. This is weird!

I have a walk behind mower that wouldn't start and I finally figured out that the safety kill lever cable was stretched and kept the engine grounded. Once I changed out the stretched cable with a new one, the mower started on the first pull every time.

So my question is - does this throttle cable on my SCOT's riding mower also work as a cut-off the electricity ground like the walk behind mower has? if so, the problem might be the same - stretched cable? Or something else going on?

I have a Yard Machine riding lawnmower that won't start. It has good gas and the oil is good. So id the battery. It turns over strong. The only way to get it to fire off is to either pour gas in the intake or cover the intake to restrict the air from intake, but it will die as soon it it fires off.

I was cutting the grass. I got off my Snapper rider to pick up trash. The mower died and won't start back up. It is like a dead battery, but the battery is good. Could it be the solenoid?

I have a Scott's riding mower with a 17Hp Briggs and Stratton motor. It won't turn over after mowing the grass last week. It needed a new battery and air filter.

I was mowing and the mower shut off. It still had plenty of gas. I changed the fuses, but all the engine did was click. The battery is fully charged. I crossed the posts on the solenoid with pliers, the engine cranked, but when I turn with the key there is only clicking.

I was mowing and stopped to move something and I killed it. When I got back on it wouldn't even turn over.

I have zero turn Z4200 riding mower and this particular day I was mowing and the mower lost power and stopped running and I tried to restart again, but wouldn't even crank over. I used a screw driver on the solenoid and it would turn over with very minimal power. I took the spark plug off and cranked it over and had a good spark and good compression as well, but when I placed my finger on the spark plug hole the compression was not enough compression to push my finger off the spark plug hole. With my finger still on spark plug hole I used a screw driver on the solenoid with my finger on the spark plug hole it has no power to push my finger off the spark plug hole.

Do I need power out of both posts on my solenoid for my mower to crank over?

I just recently cleaned out the carby on a 13hp Briggs and Stratton ride on and tipped the mower on its side to sharpen the blades, (spark plug on higher side). A fair bit of oil went through the carby, but I cleaned it out well. I put everything back together and it does the 1 click when turning it on, but won't even turn over? Can anyone help me out please?

I have a D130 John Deere tractor. The engine starts for me 220 lbs, but not for someone 150 lbs. I can start it, they get on and can't.

My mower won't fire even though I put a new plug in.

I have a Castle Garden rideon mower. I only had it running a couple of months ago (cut the garden), it was sitting up in the garage since then, now it won't start. The lights come on, everything seems OK, but it just won't start. The orange light beside the red button to get the blades cutting came on. Any help or ideas please.