If you need to mow your lawn and the lawnmower won’t start, you have a problem that can lead to quite a bit of frustration. While you should not need to use a starter fluid every time you rev up your lawnmower, it certainly can help you on occasion.
It can also help you diagnose if your lawnmower has a problem. If your lawnmower will not start up unless you use a starter fluid, it will most probably be due to one of these three conditions:
- A dirty carburetor
- A burned-out sparkplug
- Old fuel left in the gas tank
The probability that one of the above is interfering with the starting of your lawnmower increase if your mower has been sitting dormant in the garage all winter long. Another option is that you need a new lawnmower.
If every time you need to mow the lawn you need to spray starter fluid into your mower’s carburetor, something is definitely amiss. It is not routine to use starter fluid on a regular basis nor is it a recommended practice.
The “Why” of Starter Fluid
The priming of a lawnmower should not require more than three pulls to get it to start up. If your mower has been in storage for a while or maybe the engine is cold, the use of starter fluid can give it the boost it needs to get going.
It can also help you analyze a recurring problem that you may be having when trying to start it. Imagine using fluid to start the engine. It revs up and then dies out on you.
This indicates a problem with the passage of fuel. Your carburetor is probably dirty and needs to be cleaned, or it may be defective and require replacement. Other possibilities include the choke and the fuel line.
Is Starter Fluid Universal to all Lawnmowers?
Absolutely not! Some lawnmowers should never use starter fluid. Diesel engine mowers can be severely damaged when using starter fluid. Also, electric lawnmowers never use starter fluid because it is produced specifically for fuel-powered lawnmower engines.
A starter fluid for small engines is the type needed for lawnmower engines.
What Is Considered Normal Use of a Starter Fluid?
If you use your lawnmower often, using a starter fluid should not really be necessary. it is okay to use starter fluid if the machine has not been used in a while, or maybe the engine is being a bit stubborn. But if you need it often to get the engine going, there is something wrong.
If you need to hold the starter on for more than a second or two, you may eventually overheat your starter and ruin it. Also, continuous use of starter fluid can score the wall of the cylinder.
What to do When the Lawn Mower Won’t Start Without Starter Fluid
Clues About Why a Lawnmower Will Not Start
If you find that you constantly need to use starter fluid to get your lawnmower going, you need to diagnose the mower’s problem. Maybe your mower just has a dirty carburetor or dirty air filter. It may have a worn-out or bad sparkplug. It may have old fuel still in the gas tank or carburetor.
To ensure that none of these problems are the reason the lawnmower is not starting, begin with eliminating the easily resolved problems one by one.
- clean your mower’s air filter
- empty and drain completely the fuel tank
- refill the fuel tank with fresh gas
If these actions do not improve the situation, it’s time for more complex actions.
Necessary Tools and Materials
- An adjustable wrench
- Carburetor cleaner for cleaning the carburetor.
- New replacement carburetor if necessary
- A pair of needle-nose pliers
- A screwdriver
- A ratchet and socket set
- PPE gloves
Steps for Identifying the Reason you Need Starter Fluid for your Lawnmower
Step 1: Locate the sparkplug and verify if it is at all moist or grimy. Using a small bit of carburetor cleaner, remove any filthy residue from the plug. If the sparkplug appears to be dry but there is no spark, take the kill wire from the coil and check again for a spark.
Remember to replace the kill wire before trying to start the mower again. If your plug is loose, filthy or not connected it will affect the starting up of your mower, so after cleaning it should be reconnected and tightened.
Step 2: Check to see if the air filter is dirty or needs replacing.
Step 3: Our next stop is the carburetor. Should you note a chalky type of deposit, this is corrosion and is vindictive that the lawnmower needs a new carburetor. The carburetor can be disassembled. Then the pieces should be placed in carburetor cleaner for approximately an hour to soak. Reassemble the carburetor and try revving up your engine again.
Step 4: If the carburetor is not showing any corrosion, the carburetor’s main jet may be dirty. Following the instructions in the manufacturer’s lawn mower owner’s manual, using carburetor cleaner, proceed to clean the main jet.
Step 5: Another thing to verify is if the fuel line has any blockage. You can also check the fuel tank to verify if there is any type of debris inside the tank. Remove the gas line and make sure it is clear and that fuel can flow through it with difficulty.
Also check out the fuel lines to see if they are dried out and perhaps cracked. Then, you may need a new fuel line.
If there appears not to be any gas, you need to remove the gas line leading to the fuel filter. If some fuel comes out, you may need to get a new filter.
You can also try tapping on the side of the carburetor to improve the gas flow before completely replacing the fuel filter. If gas is still not flowing out, then the gas line may be jammed, and it will require replacement.
Step 5: If, however, fuel does flow to the carburetor, there may be a problem with the carburetor’s inlet needle and seat. Using a C-clamp, clamp the gas line and verify if there is gas in the carburetor bowl.
If you find an empty bowl, the inlet needle and seat will need replacing. You can also check to see if a gasket needs to be replaced.
Step 6: Check to see if the mower’s linkage closes the choke all the way. It should close completely. Sometimes the cable will slip. If everything appears okay, check to see if the choke plate is still attached to your carburetor’s choke shaft. Screws may have loosened due to vibrations.
Also, your choke may be catching or rubbing on the metal plate and not opening and closing completely.
Step 7: If you try all these steps and fuel still will not reach the engine, you need a new carburetor.
A New Lawn Mower
If after trying all the easy fixes we have listed, your lawnmower still does not run correctly, you may need a new lawn mower. At this point, it is worth it to have a professional evaluate the cost of repair and then decide that any money you spend on repairs will be better used for a new mower.
Cracked bodies and bent shafts may be too expensive to repair when the cost nears the price of a new mower. Before spending on repairs, consider:
- the age of your lawnmower
- the original cost of your lawnmower
- would you prefer another type of lawnmower such as an electric or riding mower
The occasional boost from starter fluid to get your lawnmower to start is fine, however, if it will not start without starter fluid, the mower definitely has a problem that needs to be identified and resolved.