How to Get your Lawn Mower Started - Fuel System

If you lawn mower does not start after you have made sure it is properly cleaned and free from debris (see my article "How to Get your Lawn Mower Started - Cleaning the Mower"), the next thing to do check is the fluids, (see my article "How to Get your Lawn Mower Started - Check Fluids"), the next thing to do check is the air filter, (see my article "How to Get your Lawn Mower Started - Check the Air Filter"), the next thing to do check is the spark plug, (see my article "How to Get your Lawn Mower Started - Spark Plugs and Ignition System"). After determining you have sufficient spark we will move on to the fuel system.

Difficulty: Moderate

Instructions

Things You'll Need:

• Socket Wrench Set
• Screw Driver Set
• Needle Nose Plyers
• Starting Fluid

1. First check your primer button. With the filter off, depress the button several times until you can see or smell gasoline from the throttle opening. If you are not getting any fuel here you my have a damaged line or faulty primer. The primer feeds fuel to the throttle system to help with initial start up. In time the hoses can become dry and brittle and any crack or leak will cause malfunction. A quick way to check is to spray a shot of starting fluid in the throttle opening, then try to start the mower. If it starts and continues to run, you know that it is a faulty primer system. Replace primer and hose as necessary.

2. 
    
   Marking The Bowl

   If you seem to be getting fuel here you can check the carburetor jets and float. First pinch the fuel line or drain the fuel tank to stop gas flow to carburetor (I recommend draining the tank). Before continuing to the next step make a corresponding mark from the carburetor to the carburetor bowl. This will help you line up the bowl when it’s time to reinstall the bowl to the carburetor. There may be a mark inside the bowl (F) but just to be sure, go ahead and mark it yourself.

3. 
    

   Remove screw "jet" on the bottom of carburetor bowl. Make sure you have a cup or something to capture remaining gas in carburetor bowl. Remove the gasket carefully from the screw jet and set it aside. Gaskets can be brittle and snap easily. Remove bowl and set it aside. Take a look at the bottom screw you just pulled out. It should have two small pin holes on the side and an opening on the top. This is where fuel is drawn in to the throttle body. These holes gets clogged fairly easily and is the most common problem I have found in my experience in repair. Usually you can blow from the top to clear it. Sometimes you’ll need a small needle as a tool to clear the side holes and a cotton swab to clean the tip. If you’ve determined the jet was clogged and you have cleared it, reinstall the assembly. You are finished and your mower should run for you now.

4. 
    

   4) If the screw was not clogged you will have to check the float and needle. After time your float can corrode and take in gasoline. Remove the float assembly by removing the float pin by the needle."This is a delicate operation so be careful not to bend or damage any corresponding parts."Usually you can push the pin partially out with a small allen wrench or something then grab it with needle-nose pliers to finish pulling it out. "Have a hand on the assembly because it will drop. Set aside the needle that is loosely attached to float then take a look at your float. Give it a shake and if you hear gasoline splashing around inside you will have to replace it. If this seems ok, take a look at the needle. Check the tip for corrosion or damage that would let gasoline seep through. Sometimes the tip of the needle will be rubber but not always. Replace as necessary. Again, when re-assembling the float and needle be careful not to bend or force any part or you will have to re-adjust the float settings. You can usually acquire float and needle kits from your retailer or dealer. These are inexpensive parts. Float settings should come with the instructions in your new kit. If not, ask for them.

5. These are the most common problems I have found in my experience. If this does not solve your problem you may have more serious repair problems like damaged valves, piston rings, cracked block or something of this nature. Sometimes this can be more costly and time consuming than purchasing a new Lawn-mower depending on what model you have so keep that in mind.
   I hope this information has been helpful."Now go mow that lawn"
   
   GOD BLESS,
   
   Jesse

Resources

• spark plugs and ignition system
• air filter
• cleaning mower
• fuel system
• check fluids

[mynameiswolf]

on 10/20/2008 Great article! 5*

[iamageniuster]

on 10/20/2008 Great tips. Thanks for the article. 5 stars!

[fishermon]

on 10/20/2008 Thanks alot! I was wondering if I could add links. I will go back and fix them.
Thanks again

[Miragi]

on 10/20/2008 Excelllent information!! Just a hint for your ease of writing: You can list the linkies to your other articles in the Resources section. Makes it easier for your visitors to visit them!! :)

5* Lawnmower Blades!