Hedge trimmer runs rough: Common Causes & How to Fix
1Hedge Trimmer Carburetor
Most Common Solution
Repair Instructions:
Your carburetor could be blocked. This often happens when fuel stays in the hedge trimmer for a long while. As time goes by, parts of the fuel can disappear and leave a sticky, thicker material behind. This sticky material can block the carburetor and stop the engine from starting. If your carburetor is blocked, try using a carburetor cleaning product. If it still doesn't work well after cleaning, you might need to rebuild or replace the whole carburetor.
How to Replace Hedge Trimmer Carburetor
- Disconnect the spark plug wire - Locate the spark plug wire and pull it off the spark plug. This prevents accidental starting.
- Drain the old gasoline - Tip the hedge trimmer to drain old gas from the fuel tank into an approved container. Old gas can clog carburetors.
- Remove air filter cover - Unscrew or unclip the air filter cover and set it aside to access the carburetor.
- Disconnect fuel line - Use pliers to detach the fuel line from the inlet nipple on the carburetor. Place a rag under it to catch drips.
- Remove carburetor - Take out the screws securing the carburetor's throttle linkage and choke lever. Then unscrew the carburetor's mounting bolts and carefully remove it.
- Install new carburetor - Position the new carburetor in place and reinstall the mounting bolts. Reconnect the linkage and choke lever.
- Attach fuel line - Slide the fuel line back onto the carburetor's inlet nipple and secure with a clamp.
- Replace air filter - Insert a new air filter into the cover and reattach it to the hedge trimmer.
- Add fresh gas to fuel tank - Pour fresh gasoline into the fuel tank. Use fuel stabilizer if recommended.
- Reconnect spark plug - Attach the spark plug wire back onto the spark plug. The hedge trimmer is now ready to be started.
2Hedge Trimmer Carburetor Repair Kit
Most Common Solution
Repair Instructions:
The hedge trimmer's carburetor may be blocked. This often happens when fuel is left in the trimmer for too long. As time passes, parts of the fuel can evaporate and leave a thick, sticky material behind. This can block the carburetor and stop the trimmer's engine from starting. If you think the carburetor is blocked, try cleaning it with a special cleaner. If it still doesn't work after cleaning, you may need to rebuild or replace the entire carburetor.
How to Replace Hedge Trimmer Carburetor Repair Kit
- Remove air filter cover - Unscrew or unclip the air filter cover and set it aside to access the carburetor.
- Drain fuel tank - Tip the hedge trimmer to empty the fuel tank into an approved gas container. Having no fuel in the carburetor makes disassembly easier.
- Disconnect fuel line - Detach the fuel line from the carburetor's inlet nipple using pliers. Place a rag underneath to catch drips.
- Remove carburetor - Take out the screws securing the carburetor. Unbolt the carburetor from the engine and remove it.
- Disassemble carburetor - Carefully take apart the carburetor assembly using screwdrivers. Organize parts in labeled containers.
- Clean carburetor parts - Soak all metal components in carburetor cleaner. Use compressed air to blow out passages. Avoid damaging any gaskets.
- Install new parts - Replace old gaskets, o-rings, diaphragms, etc. with identical new parts from the repair kit.
- Reassemble carburetor - Put all the cleaned parts back together in the proper order and orientation.
- Install carburetor - Remount the rebuilt carburetor onto the hedge trimmer and reconnect the fuel line and linkage.
- Test hedge trimmer - Add fresh gas to the fuel tank. Try starting the trimmer to ensure the carburetor is working properly.
3Hedge Trimmer Air Filter
Common Solution
Repair Instructions:
The issue could be that the air filter is blocked or dirty. When the air filter gets clogged up, it prevents enough air from getting into the engine. Without enough air, the engine won't be able to burn the fuel properly. This can stop the engine from starting. If your air filter looks dirty or clogged, you should replace it with a new one. Putting in a clean air filter will allow the right amount of air to mix with fuel again. This will help the engine start up normally.
How to Replace Hedge Trimmer Air Filter
- Locate the air filter - The air filter is normally housed in a plastic case that is part of the carburetor assembly. Refer to your owner's manual for the exact location.
- Open the air filter housing - Release any clamps or screws securing the plastic housing. Carefully open it up to access the air filter inside.
- Remove the old filter - Pull the dirty filter out from the housing. Make note of which direction it was facing to install the new one correctly.
- Inspect the housing - With the filter removed, check inside the housing for any debris. Wipe out any dirt with a clean rag.
- Install new filter - Place the new air filter into the housing in the same direction as the old one. Make sure it fits securely in place.
- Close the housing - Carefully reinstall the air filter housing and secure with the clamps or screws.
- Check for leaks - Start the hedge trimmer and let it idle. Make sure the housing is sealed properly and no air is leaking out.
- Perform routine maintenance - With the housing open, use compressed air to blow out any debris in the carburetor intake. Wipe any dirt away before reassembling.
4Hedge Trimmer Spark Plug
Common Solution
Repair Instructions:
Check the spark plug to see if it's worn out or damaged. If the white ceramic part is cracked, or the metal part is burned or damaged, or if there's a lot of black carbon build up on the metal part, you need a new spark plug. Use a spark plug tester to check if the spark plug isn't working right. When the engine is trying to start, you should see a bright spark between the parts of the tester. If there's no spark, it means the spark plug isn't working the way it should, and you should get a new one.
How to Replace Hedge Trimmer Spark Plug
- Disconnect the spark plug wire - Locate the spark plug wire, which will be a thin wire running from the engine to the spark plug. Pull the boot off the end of the spark plug to disconnect the wire.
- Remove old spark plug - Use a spark plug wrench to unscrew the old spark plug by turning it counterclockwise. Pull the spark plug straight out of the cylinder head when it is free.
- Inspect the old spark plug - Check the condition of the old spark plug. Look for signs of wear like corrosion, oil fouling, or a worn-out electrode. This can help diagnose any engine issues.
- Gap the new spark plug - Use a spark plug gap tool to set the gap on the new spark plug to the manufacturer's specification, usually between 0.020-0.030 inches.
- Install the new spark plug - Screw the new spark plug into the cylinder head by hand until it is finger-tight. Then use the spark plug wrench to torque it to the manufacturer's specification, usually around 20 ft-lbs.
- Reconnect the spark plug wire - Push the spark plug wire boot back onto the end of the new spark plug, securing the connection.
- Test the hedge trimmer - Pull the starter cord to test that the hedge trimmer starts up properly. Make sure the spark plug is firing correctly.
5Hedge Trimmer Spark Arrestor
Common Solution
Repair Instructions:
The spark arrestor is a tiny mesh screen that stops sparks from coming out of the engine. It can get blocked up with a carbon buildup called soot. When the arrestor gets clogged with soot, it can prevent the engine from starting. To fix this, take the spark arrestor off and scrub it clean using a wire brush. This should unclog it so it works properly again. If scrubbing doesn't get rid of the clog, the spark arrestor may need to be replaced. Putting in a new spark arrestor will ensure no soot blocks the exhaust again and allow normal starting.
How to Replace a Hedge Trimmer Spark Arrestor
- Locate the spark arrestor - The spark arrestor is part of the muffler assembly. It should be visible and attached to the muffler outlet. Refer to your owner's manual for the exact location.
- Allow the muffler to cool - Run the hedge trimmer for a few minutes to warm up the muffler. Then shut it off and allow adequate time for the muffler to cool completely before proceeding.
- Remove the muffler - Disconnect the muffler clamp or screws holding the muffler in place. Carefully slide the muffler off the exhaust outlet.
- Remove old spark arrestor - Use a socket wrench to unscrew and remove the spark arrestor from the muffler outlet. Apply penetrating oil if needed to loosen it.
- Install new spark arrestor - Screw the new spark arrestor into the muffler outlet. Tighten it securely but do not overtighten.
- Reinstall muffler - Slide the muffler back over the exhaust outlet. Reattach using the clamp or screws.
- Test hedge trimmer - Start the engine and allow it to warm up. Listen for any exhaust leaks at the spark arrestor. Make any adjustments needed.
- Perform routine maintenance - While you have access, use a wire brush to clean carbon buildup inside the muffler outlet. Wipe away debris.
6Hedge Trimmer Fuel Filter
Common Solution
Repair Instructions:
The problem could be that the fuel filter is blocked. This often happens because old fuel was left in the hedge trimmer. Over time, some of the chemicals in the fuel can evaporate. This leaves a thick, sticky substance. This sticky material can get stuck in the fuel filter. When the filter gets clogged, it stops the engine from starting properly. If you left old fuel in the trimmer, first drain it out of the fuel tank. Then replace the fuel filter. This should allow fresh fuel to flow correctly again so the engine will start up.
How to Replace Hedge Trimmer Fuel Filter
- Prepare the work area - Clear a flat, sturdy work surface that allows ample room to work on the hedge trimmer. Spread out some newspaper or a drop cloth to catch any spilled gas or oil.
- Disconnect the spark plug - Locate the spark plug on the engine and disconnect it. This prevents accidental starting while working on the fuel system.
- Access the fuel filter - Refer to your owner's manual to locate the fuel filter. It is typically inline along the fuel line. You may need to remove a plastic cover or the air filter housing to access it.
- Remove the old filter - Use pliers to grip the fuel line on both sides of the filter. Compress the clamps and slide them away from the filter. Pull the filter out from the fuel line.
- Install the new filter - Slide the clamps over the ends of the new filter. Push the filter into the fuel line, centering it between the clamps. Slide the clamps against the filter and compress them to lock the filter in place.
- Reconnect spark plug - Once the new filter is securely installed, reconnect the spark plug wire.
- Test the trimmer - Add fresh gas to the fuel tank. Start the engine and let it run to check for leaks at the fuel filter. Make any adjustments needed.
7Hedge Trimmer Air Filter
Common Solution
Repair Instructions:
The issue could be that the air filter is blocked or dirty. When the air filter gets clogged up, it prevents enough air from getting into the engine. Without enough air, the engine won't be able to burn the fuel properly. This can stop the engine from starting. If your air filter looks dirty or clogged, you should replace it with a new one. Putting in a clean air filter will allow the right amount of air to mix with fuel again. This will help the engine start up normally.
How to Replace Hedge Trimmer Air Filter
- Locate the air filter - The air filter is normally housed in a plastic case that is part of the carburetor assembly. Refer to your owner's manual for the exact location.
- Open the air filter housing - Release any clamps or screws securing the plastic housing. Carefully open it up to access the air filter inside.
- Remove the old filter - Pull the dirty filter out from the housing. Make note of which direction it was facing to install the new one correctly.
- Inspect the housing - With the filter removed, check inside the housing for any debris. Wipe out any dirt with a clean rag.
- Install new filter - Place the new air filter into the housing in the same direction as the old one. Make sure it fits securely in place.
- Close the housing - Carefully reinstall the air filter housing and secure with the clamps or screws.
- Check for leaks - Start the hedge trimmer and let it idle. Make sure the housing is sealed properly and no air is leaking out.
- Perform routine maintenance - With the housing open, use compressed air to blow out any debris in the carburetor intake. Wipe any dirt away before reassembling.