Experienced gardeners share their insights in answering this question :
Need Make/Model/Year/Engine Model/Deck Size, and hours on meter if you have one. A short description of the events preceding the beginning of the problem is also helpful.

The are quite a number of possibilities based on your description. Further details will help narrow it down. The following post covers a few basics. If these don’t help add information to your post.

Let’s say you have less than 300 hours on the engine. Let’s further assume it worked last summer, or last week, but now it’s acting up. Let’s also verify the battery is in good shape and fully charged. I am also assuming the engine cranks when you turn the key, but it just doesn’t start.

A mechanically functional (meaning all the internal parts are working, i.e. pistons, valves, etc) engine requires 3 things, air, fuel, spark. So the quickest way to start your diagnostics is to remove the cover over the air filter and then remove the air filter. I do not recommend spraying Quick Start.

remove air filter (set it aside for the rest of the diagnostics)
put throttle on fast run (do not choke)
pour an ounce or two (a shot glass) of fresh gas into the carburetor
crank engine (15 to 20 seconds, rest to cool the starter, repeat 3 times if it does not fire at first).

Removing the air filter and placing the throttle at full speed with no choke eliminates the “air” question. Dumping in the fuel eliminated all fuel related questions. What’s left? Spark. If the engine fires and runs a bit, then dies, you have eliminated the spark question. The engine started so Spark and Air are good; you have to track down a fuel problem.

If the engine does not fire, you have eliminated the Air & Fuel questions; you must tract down a Spark problem.

Tracking down fuel problems.

Make sure there is plenty of fresh fuel in tank.
Remove fuel line from filter and remove the filter, gas should pour out of the hose coming from the tank. If it does not, remove gas tank cap. If fuel flows now, you need to unclog the cap vent or replace the cap. If the fuel still does not flow then blow air from the filter end of the hose back up through fuel line to blow out blockage inside the gas tank. Once you have fuel flowing out the line to the filter, PUT ON A FRESH FILTER. Try cranking the engine. If it still does not start move on to the carburetor.
Note: many systems have a fuel shut off solenoid. This is a small black cylinder on the bottom of the carburetor. It has two wires running to it. It should make an audible click when you turn the key on.
NOTE: if battery voltage drops below 9 volts when cranking or while the engine is running, the fuel solenoid will not function. That means the engine will not start or will die soon after starting. So check your battery voltage before, during, and after cranking. If the battery voltage is good before but drops below 9 volts while cranking this is generally a sign the battery has one or more bad cells. Replace the battery. If the battery is in fact good and the voltage is still dropping you may have a bad starter motor and it is drawing too much amperage.
Ck to see that the carburetor bowl is full of fuel, if not…you may have to disassemble and clean the carb at this point.

Tracking down Spark problems.

verify battery fully charged.
verify the fuel cutoff solenoid clicks when you turn the key switch
get fresh spark plugs and verify gap
install plugs and crank. Perhaps verify spark with a spark testor

If these simple steps do not solve the spark problem, you have a Spark problem that moves into the arena of complex. You will need to check coil gap and coil performance. If it still doesn’t start you will need to diagnose the electrical system for wiring and safety switch problems, key switch problems, fuses, etc.

A Problem of Air Control.
If you determine the Spark & Fuel systems are good, the next likely problem is Valve adjustment out of wack. This is a problem of Air Control (and its sister compression), the third element in the engine trinity. Usually this problem shows up as backfire; either back through the carburetor or out through the exhaust. It will backfire while you are trying to start it. HOWEVER, it does not always generate backfire. You may instead notice that the engine spins more freely than usual; or oddly enough just the opposite and the engine bind while you are cranking it. This is because the compression is lost by out of wack valves or the compression is out of sync with the spark. You need a valve adjustment.

Once you get it running be sure to replace the Air Filter with a new one.

These simple steps solve most starting and running questions and problems.

How to Identify and Fix Common Gardening Problems ?

We provide a variety of viewpoints on how to identify and fix common gardening problems. Our sources include academic articles, blog posts, and personal essays from experienced gardeners :

Check/clean/tighten all connections on battery/solenoid/starter/Ignition switch and neg(-) cable to frame or motor. Check to ensure all safety features are working properly and not engaged. Check for an inline fuse, bypass solenoid to see if engine cranks if it does replace solenoid, if no crank replace starter.
Loose, Dirty or Disconnected Spark Plug in Your Lawn Mower: Check it out, clean off debris, re-connect and tighten. Dirty Air Filter: Clean or replace. Fuel Not Reaching the Engine: Tap the side of the carburetor to help the flow of gas. If this doesn`t work, you might need a new fuel filter.
The most common cause for the engine not turning over is simply the battery. Either the battery itself is dead, the terminals are corroded so the current can`t travel through them, or the battery cables themselves are damaged. Inspect your battery terminals and cables, and test the battery.
How can I tell if my ignition switch is failing? A bad ignition switch will have problems with starting the engine, keeping it running, or engaging other systems when the key is turned. You might also have issues turning the key.
Loose, Dirty or Disconnected Spark Plug in Your Lawn Mower: Check it out, clean off debris, re-connect and tighten. Dirty Air Filter: Clean or replace. Fuel Not Reaching the Engine: Tap the side of the carburetor to help the flow of gas. If this doesn`t work, you might need a new fuel filter.
Why does the tractor make a clicking sound and not start? If the riding mower makes a heavy clicking or a rapid clattering sound when the key is turned to the start position, there is a problem with the battery or a part of the starting circuit. The clicking noise comes from a part called the starter solenoid.
Touch the metal shaft of a screwdriver to both of the large terminals at the same time. If the engine turns over and starts, the solenoid is bad and should be replaced. If the starter motor does not run, the motor itself is probably defective.
Position the red probe on your ignition switch.

Put the black probe on any exposed, unpainted metal surface in your vehicle. Then, look for a gold or silver terminal on the side of your ignition module. Hold the positive probe against the terminal to test the ignition switch.

Put the key in the run position, set the multimeter to 20 DC voltage, ground the black lead on any metal surface close by, and place the red lead on a connector at the opposite side of the ignition cylinder. If the multimeter displays a reading far from your battery voltage, the switch is bad.

Discover Relevant Questions and Answers for Your Specific Issue

the most relevant questions and answers related to your specific issue

Tractor ran out of gas, put more in, now won’t start again
ANSWER : Is it diesel ? Do you have a way to prime the fuel supply (fuel priming pump) ?

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Toro lawn and garden tractor will not start all of the stafety switches are working and the battery is charged but the safety relay will not energize.
ANSWER : Remove the two wires going to the switch and use a jumper wire to bybass the safety switch if it starts replace the switch, make sure power is getting to the relay, relays have two power wires one that activates the relay coming from the physically activated safety switch the other is a power wire that is activated by the ignition switch, you must have power to the relay with ignition key on.

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Lawn tractor won’t start has charged battery ignition key will not start when fully turned to the right.I have started it by jumping the contacts on the solenoid. but now that won’t work
ANSWER : There are several kill switchs one is at the deck lowering handle , others are on the gearshift , you probably burnt out the solinoid using the screwdriver its and easy replace? these are also bad on starters they burn up quick? if you go to type in your model # it will show you expolded veiw of the switchs with a test light and a little mech ability you can fix it ? hope this helps

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Wont start I charged the battery and all I’m getting is a clicking sound when trying to start
ANSWER : Your battery is junk. Replace it. Lead/acid batteries lose about 1% of their charge per day, so in 90 days of non-charging they are basically discharged. This is a bad thing. When winter comes, put a smart trickle charger on it, or at least once a month put a non-smart trickle charger on it for a couple hours or an afternoon so you keep it charged up.I love/hate batteries.

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Ford truck150 xlt triton 2007starter
ANSWER : Check that battery has full power Check terminals are clean and tight. If starter is old and done a lot of work check brushes for wear. If worn may need complete overhaul. Check that holding studs are tight.

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1989 JD 2155 2WD tractor, cannot start engine, have replaced starter switch, nothing happens, battery good. What should I check next?
ANSWER : Have you tried crossing the large post of the starter with the small terminal that has the engagement wire going to it[with the machine in neutral and the range lever in neutral if course].If this will make the tractor turn over then the problem is likely the neutral safety switch located under the panel that is covering the transmission just rear of the sticks.

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I have a Sears 26 hp garden tractor that stalls when I let off of the clutch/brake or engage the mower blades. I have bypassed the under seat swith, and I have also bypassed the clutch/brake switch. The mower will not stall out untill I engage the mower. Any ideas on what else might be the problem?
ANSWER : Does it run off of a pto system or is it a lver type if its a lever type there is a switch under the lever also you might have something caught in the deck causeing it not to engage blades if i can further help e-mail me wade at [email protected]

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My cub cadet won’t start just clicks ,i changed the fuse and tryed to jump start it no luck what do i do now?
ANSWER : Check your soleniod.

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