Leaf Blower Dies When Choke is Off

Leaf blowers are trusted landscaping tools year-round, so a spotty motor can be a real interruption to your home maintenance routine. If the engine is stalling or shutting off after ignition, it’s likely due to one of a few things that you can repair yourself.

An inspection and some maintenance should get the blower back running so you can get back to yard care.

What Is The Choke On A Leaf Blower?

When a gas powered leaf blower starts up, the engine is normally going to be at room or air temperature. This is known as a cold start, relative to the temperature it heats up to.

When you turn on a cold engine, the choke valve cuts off the air supply so that the fuel in the carburetor’s combustion chamber burns “rich.” It’s called this because there is a high fuel to air ratio, which warms up quickly and heats the engine metal.

After several seconds, the engine is warm, and the choke turns off by opening up and allowing air to flow into the carburetor, either automatically or manually by the user. A balanced air to fuel ratio burns efficiently, but when too much air is added to the ratio (burning “lean”), the engine stalls and shuts off because not enough power is being generated.

Too much air is usually a result of too little fuel being supplied to the carburetor. If there’s not enough fuel flowing, air will fill the chamber and cool it off, winding down the power supply and turning off the engine.

Do You Run A Leaf Blower With The Choke Open Or Closed?

Do You Run A Leaf Blower With The Choke Open Or Closed

When running a leaf blower, the choke is normally off or open after ignition. Sometimes an engine needs a little burst of fuel if it is stalling, in which case you can use the throttle to add more fuel into the carburetor’s combustion chamber and increase the fuel to air ratio.

If you need to leave the choke closed for the blower to operate, there is a problem that should be investigated. When an engine runs with the choke closed, it burns a lot of fuel quickly and can cause damage to the engine from overheating. Normally, air intake will prevent this and leave the fuel burning at an even, efficient rate.

How To Use The Choke On A Leaf Blower

A leaf blower’s choke may be automatic or manual, but in either case, it is essential only at ignition. The warm-up period might take a few moments, however, with certain leaf blower models requiring between 15 and 30 seconds to raise the engine metal’s temperature.

Sometimes a half choke setting will be best for your model to heat up at an even pace. If the leaf blower only runs on choke, shut it off and inspect it for potential maintenance needs.

Checking The Fuel Flow

An interruption in the fuel flow is usually the answer to why the engine needs to run with the choke on. Check the fuel level to ensure it isn’t low, then check on the fuel delivery system. You’ll want to look out for these potential issues:

  • Clogged fuel filter
  • Fuel line leak
  • Clogged fuel intake

Whether you have a Stihl, Echo, or Husqvarna brand leaf blower, carburetors and fuel tanks are all made more or less the same. These issues are typical for any brand or model after a while of use, and your unit’s manual will let you know if there are any special instructions for maintenance, replacements, or repair.

Clogged Fuel Filter

Clogged Fuel Filter

To check the fuel filter, empty any fuel in the tank into a container before you start. Fish out the fuel line using a long bent or hooked wire, which hangs in the tank. The filter is connected to the fuel line, and you will be able to see whether or not it has absorbed enough buildup to block intake.

This will happen eventually, so if you haven’t checked it recently, it may be the reason your leaf blower’s engine is stalling or shutting off.

Attaching a fuel filter replacement is an easy task, and your model’s manual will tell you what kind of filter you need. The smaller the filter, the more often it should be replaced. Keep an eye on your filter since leaf blower motors are smaller than other lawncare equipment.

Fuel Line Leak

When you’re inspecting the fuel filter, check the fuel line as well. Fuel lines can get brittle or stiff and may crack or break over time. Leaks or broken tubes will interrupt the fuel feed and need to be replaced.

There are usually two tubes that are connected to form the single fuel line from the tank to the carburetor. One line is in the tank, and the other is between the tank and the carb. The tubes are linked by a connector, which fastens with a grommet or a rubber seal in the tank.

To inspect the internal fuel line, you’ll have to remove the screws and lift off the cover of the leaf blower. The carburetor will be located next to the fuel tank, behind the air intake valve, and connected to the tank by the fuel line tubes.

Replacing one or both of the tubes is an easy task, as they should snugly fit around the connector pins and slide off and on with a little force.

Clogged Fuel Intake

As fuel is used, the liquid is turned into gas, and solids are left behind. When fuel is stored in the tank for an extended period of time, some of it will evaporate and similarly leave residue as the liquid dries up.

The fuel filter is meant to prevent this by catching solids in the gasoline, but it doesn’t catch everything. Buildup can occur in the tubes, the connector, or the carburetor.

Leaf air blower and gas can

Examine the filter, connector, or tubes and replace them as necessary. Carburetor cleaner will help with buildup that may be blocking the fuel chamber and keep the engine in good repair.