Lawn Tractor: Hard To Start

The battery in your lawn tractor provides power to the starter, which allow the engine to turn over, and ultimately run on its own. A dead or weak battery will not be strong enough to apply the amount of power required by the starter. To test the battery, take a digital multi-meter and switch it to DC and 13V. Place the red lead on the battery’s positive terminal and the black lead on the negative terminal. Replace the battery if it reads below 10.5 volts. To replace the battery, first remove the cables (starting with negative) and remove any hold down clamps. Now you can install the new battery.

The carburetor mixes air and fuel together in the proper mix for combustion. A clogged carburetor can make your tractor difficult to start, as it can starve your engine of fuel. To inspect and/or replace the carburetor, first remove the air cleaner cap, and locate the carburetor. Next, clean out the carburetor using carburetor cleaner and a soft brush for the inside. Check that the choke valve is functioning properly; it should be closed to allow the air fuel mixture to be rich for starting. If it is not functioning properly it may require a new cable, rod or switch depending on the model and how it is attached, as different models are set up differently.

The air filter is located on top of the carburetor. Its main function is to allow clean-flowing air into the engine and prevent small particles from damaging internal engine parts. Over time the air filter will need to be replaced as it becomes clogged with small particles and debris, starving the engine of air and power. This can also make the engine difficult to start. To inspect the air filter, simply remove the air filter cover by the tabs or screws that hold it in place. If it looks heavily soiled, it will need to be replaced.

The fuel filter is located between the fuel tank and the carburetor and prevents debris from entering the carburetor and them engine, potentially causing damage. You can remove the fuel filter by gently twisting the fuel line off from both ends and blowing through it. If it is blocked, then you will need to replace it. Once the fuel filter is unclogged, it should make your starting your lawn tractor much easier. Regular inspection and cleaning of the fuel filter should be done as part of your regular lawn tractor maintenance routine.

The gasket in your lawn tractor seals off air and fluids from entering areas where they can cause damage. A damaged gasket below the carburetor will pull excess air into the cylinder, causing a hard-to-start situation. To check the gasket, start by removing the air filter and loosening the carburetor bolts. At this point you can check the condition of the gasket. You will want to look for tears, rips, or any indications of leaks. Gaskets are designed for one-time use so you will have to replace it at this point regardless of condition. Finally, re-assemble the gasket, carburetor, and air filter in reverse order.

The spark plug’s job is to ignite the air/fuel mixture in the combustion chamber. If the spark plug is malfunctioning, your lawn tractor will be difficult to start. To check that the spark plug is functioning properly, first remove the wire from spark plug; be careful doing so, as they are fragile. Next, remove the spark plug and check its condition. A spark plug’s normal color should be a light brown or grey. If the plug is dirty, you should first clean it, and then re-gap to the manufacturer’s specifications. Also check for any deposits, breakage, melting, and corrosion. If you see any of these symptoms, replace the plug and gap to the manufacturer’s specifications.

The starter’s job is to turn the engine over, so it can run on its own. When power is applied, a small gear makes contact with the flywheel, which spins the engine over. To check the starter, connect a jumper wire from the battery’s positive terminal to the starter, and the other jumper wire from the negative terminal on the battery to any metal part of the tractor. If the starter turns over, then it is in proper working condition. If it does not, then it’s likely that a bad starter is making your tractor difficult to start, and it will need to be replaced. To replace the starter, first disconnect the battery. Then, disconnect the wires from the starter, undo the bolts holding starter in place, and remove the starter. At this point you can simply replace the bad starter with a new one, reattach the bolts, and wires, and reconnect the battery.

A solenoid is an electrical switch that uses a small current to control a higher current. A small current is used to energize a coil that will pull a magnetic switch into place, and allow the flow of a high current, and shut off the high current as well. There are both 3- and 4-pole solenoids, however most are of the 3-pole variety. When it comes to 4-pole solenoids, the fourth pole is a ground, whereas the 3-pole solenoid grounds itself out when bolted down. To test your solenoid, use 2 jumper wires and attach the alligator clips to the positive and negative terminals of the battery. Next, attach the negative wire to ground on the solenoid (clip onto the back for a 3-pole model, or the negative terminal in a 4-pole model), and attach a volt meter to both large terminals on the solenoid. Now, attach the positive jumper from the battery to the small connection on the solenoid. You should hear it click into place and if the solenoid is in working condition, the volt meter will read 12 volts. If you do not hear the switch click or see 12 volts, the solenoid will need to be replaced.

Fuel lines deliver fuel from the tank to the carburetor, where it is mixed with air for combustion. Pull the fuel line off the carburetor gently in a twisting motion and do the same on the fuel tank and fuel filter. You can simply blow through the lines looking for anything unusual coming out. If you cannot blow through a line, it is an indication that you have a blockage. Lines should also be replaced if they look old and cracked, as they could leak and cause a fire.