Skip to Content

How to Fix a Toro Lawnmower? Diagnose the most common problems with fixes

Toro is one of the most popular lawnmower brands. The lawnmowers from Toro are generally considered strong and reliable. But even the best machines can malfunction sometimes, and your Toro lawn mower is no exception. Several issues could prevent a Toro lawnmower from starting or working at its best. Such problems include gas and oil-related issues, dirty air filter, dirty carburetor, faulty spark plug, etc. Curing most of these problems is generally easy, but new Toro lawnmower owners might get confused. In this case, a detailed guide on these problems and how to solve them will surely come in handy. In this blog post, we’ll explain some common issues that can halt your good-quality Toro lawnmower and their possible fixes.

How to fix a Toro lawnmower. Diagnose the most common problems with fixes:

  • Bad Gas: It can clog the carburetor and fuel line. Remove old/bad gas and add fresh gas before you start mowing. Avoid gas with more than 10% ethanol.
  • Oil Related Issue: Oil-related issues can cause overheating and smoke. Always use the right amount of the correct oil grade.
  • Dirty Air Filter: It can block the supply of fresh air to the engine. Clean or replace the dirty air filter.
  • Dirty Carburetor: A Toro mower with a clogged carburetor won’t start or lose power and efficiency. Remove, disassemble and clean the dirty carburetor.
  • Faulty Spark Plug: A faulty spark plug fails to ignite the fuel-air charge in the combustion chamber. Remove, examine and clean the spark plug and adjust the spark plug gap.
  • Broken Primer Bulb: It will fail to supply fuel to the engine when you try to start the mower. Replace the primer bulb or prime your mower without the primer bulb.
  • Dull Blades: Will give an ugly look to your lawn. Sharpen the blades and replace them if they are too damaged.

Common Toro Lawnmower Problems and their Solutions:

● Bad Gas:

Gas stored in a Toro lawnmower’s fuel tank for more than thirty days can go bad because of evaporation and oxidation. Stored gas produces a thick gum-like structure that clogs the carburetor and the fuel line. A clogged carburetor fails to provide the correct fuel-air charge to the combustion chamber, which results in the engine failing to produce adequate power. In the most severe cases, an engine doesn’t even start because of a clogged carburetor or starts and runs for some minutes before suddenly shutting down.

– Fix:

If your Toro lawnmower is not starting or observing a decrease in its power, especially after using the mower after a long time, bad gas could be the reason. To fix this issue, drain the old gas and thoroughly clean the fuel tank and the fuel filter. You might need to clean the fuel line too if it has become clogged. Then remove the carburetor and clean it using carburetor cleaner. We will provide more details on how to clean a carburetor in the dirty carburetor section.

Once done with the things mentioned above, pour fresh gas into the tank and start the mower. Let it sputter for four to five minutes before using it again.

– Gas related tips:

Always use the gas recommended for your mower by Toro. Try to use fresh gas each time you mow. The use of a gas stabilizer is recommended to keep gas usable for a longer period. Try to avoid gas with more than 10% ethanol for the best performance and health of your Toro lawnmower.

● Oil Related Issues:

There are a few things that could affect your Toro lawnmower’s operation when it comes to oil. First of all, using the right level of oil is essential. If your Toro mower’s crankcase has too little oil, it will lead to overheating of the machine, and the engine will stall. Secondly, oil spilled on and around the engine housing or oil overfilling can result in your mower producing white smoke. Using too little oil or an incorrect oil grade can result in excessive wear and tear of the moving parts, causing extreme damage to your mower.

– Fix:

If your Toro lawnmower is overheating, inadequate oil could be the reason. So, turn off the engine and let the mower cool. Then check the oil level in the crankcase using the dipstick. The oil level should be close to the top limit but not above it. If the oil level is low, add more oil and keep checking with the dipstick until the correct oil level is achieved.

If your mower is blowing white smoke, it could be because of oil spilled on the engine housing. Stop mowing but let the mower run until all of the spilled oil is consumed, or turn off the engine, let it cool down, and then clean the spilled oil with a rug. Too much oil in the crankcase can also result in white smoke. If that’s the case, drain the excess oil until the correct amount of oil is left.

It is our advice to use the oil recommended for your machine by the manufacturer. Oil grades reflect oil’s properties such as viscosity and heat absorption etc. Always use the right oil grade for your Toro lawnmower.

● Dirty Air Filter:

A dirty air filter can be the prime reason behind the combustion chamber not receiving enough fresh air from the atmosphere. Without fresh air reaching the combustion chamber, your Toro mower will not function perfectly. Over a long period of use, dust, grass debris, and oil residue can clog the air filter.

– Fix

You can fix a dirty air filter by washing it with soap and water using a brush. Remove your Toro lawnmower’s dirty air filter and wash it clean. Then let it dry completely before installing it again. If the air filter becomes too dirty to clean, it would be best to replace it with a clean new air filter. If your Toro lawnmower is using a paper air filter, you can not clean it, and if it has to be replaced.

● Dirty Carburetor:

As mentioned before, the gas stored in the tank for a long time can harm the carburetor by producing a thick gum-like substance that clogs the carburetor. A clogged carburetor fails to provide fuel-air charge to the combustion chamber, which either prevents the mower from starting or reduces its power and efficiency. So, it would be best if you cleaned a dirty carburetor at the earliest.

– Carburetor Cleaning:

First of all, take off the carburetor from your Toro lawn mower engine by removing the screws holding it in place, then disconnect it from the fuel line. Make sure that the fuel valve is closed while you are working on the carburetor. You may need to wiggle the carburetor to remove it.

The next step is to open the carburetor. For this purpose, unscrew the carburetor’s top cap, and you will have a removed spring and throttle slide. Unscrew the four screws to dismantle the upper cap of the carburetor. You’ll see a greasy dusty float connected with the float bowl but do not start cleaning it yet. Now remove the float pin and place the removed float pin, and float into a small container with the other parts. Carefully remove the main jet and pilot jet along with the float needle valves, gaskets, and O-rings.

The container now contains all the parts from the Toro carburetor that you disassembled. The quickest way is to soak the items in gasoline to remove greasy lumps and dust. After soaking the components for a while, take a wire brush and scrub the pieces gently. Spray the carburetor cleaner into the float cap’s holes and on the main carburetor body and valves; then air-dry the pieces with an air compressor’s help. When cleaning is done, install brand new O-rings and gaskets, and reinstall the fuel jets, pilot jets, float, and float pin one by one. You may reuse the old O-rings and gaskets if they are in good condition. Clean them, too, before reinstalling.   

● Faulty Spark Plug:

The spark plug provides a spark to ignite the fuel-air charge that reaches the combustion chamber. If the spark plug is faulty, the fuel-air mixtures will not ignite perfectly, and your Toro lawnmower will lose power. If the spark plug is too damaged, your mower will not start.

– Fix

Remove the spark plug by first disconnecting the plug lead and then taking out the plug using a wrench. Examine the plug for moisture and carbon deposit near the electrodes. Clean and dry the spark plug with a rug. Remove the carbon deposit using a metal file or sandpaper. Measure the spark plug gap using a feeler gauge. The gap should match the standard plug gap mentioned in the Toro user manual. If the gap is too little or too large, adjust it too. If the spark plug insulator sheath is broken, replace the spark plug with a new one.

● Broken Primer Bulb:

The primer bulb’s job is to create a fuel-rich condition by sending extra fuel into the engine. To start the engine, the user has a rubber primer bulb mounted at the carburetor to send fuel to the engine. If the primer is broken or damaged, fuel will not reach the engine when you try to start the engine so that the engine won’t start.

– Fix

Replace the primer bulb with a new one using a replacement kit. You can still temporarily start your Toro mower with a damaged primer bulb by squirting starter fluid into the air-intake hole so that a fuel-air mixture reaches the engine. The air intake is located behind the air filter, so you’ll have to remove the air filter for this procedure.

● Dull Blades:

After a long period of use, the blades of your Toro lawn mower will become dull. Dull or damaged blades don’t cut the grass cleanly, which results in the grass turning brown, and it can even cause grass diseases to spread.

– Fix

It would be best if you regularly sharpened lawnmower blades for best cutting and grass health. You can sharpen the blades using a metal file or grinder. It would be best if you replaced chipped, cracked, and bent blades with a new set at the earliest.

Final Remarks:

Many common problems can affect your Toro lawnmower over its life. A lot of issues can be solved easily. In addition to the guideline provided in this blog post, you may also consult your manufacturer or online video tutorials to fix your Toro lawnmower.