You are only able to keep your blower running by closing the choke. Having to restrict airflow to keep it running not only affects performance but also indicates you have an underlying problem that must be repaired.
A Troy-Bilt leaf blower will only run with the choke on when the engine isn’t getting enough fuel or is getting too much air.
This is a result of old gasoline, a dirty carburetor, a bad carburetor gasket, a plugged fuel vent, a restricted fuel line, a plugged air filter, or a puncture in the fuel line.
Before making repairs, wait for the engine to cool and for all parts to stop moving. Remove the spark plug boot and follow all additional safety precautions outlined in your Troy-Bilt operator’s manual.
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Follow all safety instructions provided in your equipment operator’s manual before diagnosing, repairing, or operating. Consult a professional if you don’t have the skills, or knowledge or are not in the condition to perform the repair safely.
6 Reasons a Troy-Bilt Leaf Blower Only Runs With the Choke On
1. Old Gas
Old gas is often the main culprit for fuel restrictions and component failures.
When you are not getting enough fuel to the engine, the choke may need to be used to correct the ratio of fuel-to-air required to keep the blower running.
Most gasoline contains ethanol which can leave varnish and sticky deposits in the fuel system as the fuel ages.
It’s important to use fresh gasoline with a low ethanol content to reduce problems developing in the fuel system as a result of gas. Use unleaded gasoline with a minimum 89-octane rating and no more than 10% ethanol.
Troy-Bilt leaf blowers with 2-cycle and 4-cycle engines have different fuel requirements.
- Troy-Bilt 2-cycle leaf blowers require a fuel mixture of gasoline and premium air-cooled 2-cycle engine oil. Gas and oil are mixed at a ratio of 40:1.
- Troy-Bilt 4-cycle leaf blowers require a straight gas. Do not mix gas and oil for these types of engines. There will be a separate fill port for SAE 30 engine oil.
Find out more about the right fuel to use in your Troy-Bilt and how to care for it in This is the Type of Gas & Oil Mix Troy-Bilt Leaf Blowers Use.
2. A Clog or Puncture in the Fuel Line
You may have to use the choke when there’s a restriction in the fuel line from old fuel or dirt buildup in the fuel line. It may also be the result of air being introduced through the fuel line.
Fuel lines that become cracked or punctured can allow extra air to be sucked into the fuel system. Because of this, the choke must be on to minimize the amount of air through the air intake.
SOLUTION: Remove and replace any clogged, damaged, or cracked line and replace it with a new fuel line. Make sure the fuel lines are securely attached to seal the fuel system so extra air isn’t sucked through the lines.
3. Plugged Fuel Filter
A fuel filter is used to keep dirt from entering the Troy-Bilt blower’s fuel system. It can restrict fuel flow when it isn’t changed regularly and becomes plugged with dirt and debris.
I recommend replacing the filter annually to avoid running into this problem. You will need to change it more often if you add dirty fuel to the tank.
SOLUTION: Replace a plugged fuel filter. The fuel filter is located inside the fuel tank on a Troy-Bilt blower. Wipe around the fuel tank cap before removing it to keep dirt from falling into the tank.
Replace a Troy-Bilt leaf blower fuel filter:
- Remove the cap.
- Take note of the placement of the filter so you place the new filter in the same position.
- Pull the fuel filter out of the fuel tank. A clean bent wire works well to retrieve the filter.
- Once the filter is out of the tank, remove it from the fuel line.
- Attach the new fuel filter by inserting the male end into the fuel line and making sure it is securely attached.
- Place the fuel filter back inside the fuel tank.
- Install the fuel cap.
4. Bad Carburetor Gasket
There is a gasket that sits behind the carburetor that can deteriorate and become bad. A bad gasket will cause the carburetor not to seal properly and allow air into the system.
The Troy-Bilt blower will run lean resulting in the choke needing to be on to restrict the amount of air mixed with fuel so it no longer runs lean with a higher concentration of air being mixed with fuel than the engine requires.
SOLUTION: Gain access to the carburetor and carefully remove the linkages and bolts attaching the carburetor. Remove the carburetor and gasket.
Reinstall a new gasket on your Troy-Bilt and reattach the carburetor, bolt, and linkages. You may need to clean the carburetor while it is off the leaf blower.
Note: Once you remove the carburetor to inspect the gasket, you will need a replace it whether it is bad or not. Have a replacement gasket available.
5. Dirty Carburetor
The Troy-Bilt carburetor’s function is to regulate the amount of fuel that is mixed with air to form combustion to start and run the leaf blower.
A buildup of varnish and deposits can make the carburetor not function as designed so it isn’t able to get fuel to the engine.
SOLUTION: If you are a little mechanical you should be able to handle cleaning your carburetor. Clean the carburetor by taking it apart and using carburetor cleaner to remove deposits left behind from old fuel.
If the carburetor does not function after being cleaned, you may need to rebuild it or replace it with a new carburetor. Your Troy-Bilt dealership or small engine dealer can also clean or replace the carburetor for you.
6. Clogged Fuel Tank Vent
Another item that can cause a fuel restriction is the fuel tank vent. This vent is located in the fuel cap on most Troy-Bilt leaf blowers. When the vent becomes clogged, the air isn’t able to pass through the cap.
A vacuum will form in the fuel tank keeping fuel from flowing out of the tank. To determine if your fuel cap is causing you to have to run your Troy-Bilt with the choke on, place your leaf blower on a level surface to avoid fuel spillage.
SOLUTION: Remove the cap while allowing your blower to run. Adjust the choke to the off position to determine whether or not the blower will continue to run with the choke off.
If the engine runs fine after allowing air into the fuel tank, your fuel tank vent is most likely the problem. Replace the fuel cap with a new Troy-Bilt cap.
Still Experiencing Problems with Your Troy-Bilt Leaf Blower?
If you’ve gone through the list above and continue to have problems with your blower, check out my guide for troubleshooting and repairing Troy-Bilt blower problems.
Here I provide charts with causes and solutions to the top common problems that develop in a leaf blower. You will find links that explain the issue and solutions in more detail.
To reduce the problems developing the blower and extend its life, perform regular maintenance. This includes cleaning or replacing the air filter, replacing the fuel filter, replacing the sparking plug, and keeping it clean.