TL;DR
A trimmer that stops feeding line almost always has grass wrapped tight around the shaft under the head, and clearing it takes about ten minutes. Kill the power first: pull the battery, or disconnect the spark plug lead on a gas unit, before anything comes apart.
Power off means power off
On a battery trimmer or blower, remove the battery pack entirely. Setting the switch to off is not the same thing.
On a gas unit, disconnect the spark plug lead and tuck it away from the plug. Turning a cutting head can turn the engine, and an engine can fire on compression.
On a corded electric, unplug it at the wall and confirm the plug is out.
Let a gas engine and muffler cool fully first. The muffler is hot enough to cause a serious burn well after the engine stops.
Wear gloves and eye protection. The debris packed into a trimmer head is full of grit, sticks, and sometimes wire.
Never clean any equipment with gasoline or a flammable solvent, and never run a gas engine indoors. Carbon monoxide from a running engine is the hazard, not the mess.
Why is my string trimmer not feeding line?
The most common cause is grass and stem material wrapped tightly around the shaft between the head and the guard, which binds the spool so it cannot rotate and release line. Welded or fused line inside the spool is the second cause, and it happens when the line heats up from hitting fences, curbs, or hard ground.
Clearing the wrap fixes it far more often than any adjustment does.
Line that has fused into a solid lump has to be pulled out and rewound. It cannot be freed in place.
Line that has dried out and gone brittle also breaks constantly. Trimmer line is a consumable and old line snaps.
Clearing the head and the shaft
Take the spool cap off and remove the spool. Most twist off or release with two tabs.
Look at the shaft under the spool. That is where the wrapped grass hides, and it will be packed hard.
Cut the wrap free with a utility knife, working carefully so you do not nick the shaft, then pull it off with pliers.
Brush and blow out the head housing. The eyelets that the line passes through collect grit and wear, and worn eyelets shred line.
Wipe the spool and check it for grooves. A deeply grooved spool binds the line and is a cheap part to replace.
Rewind the line neatly and in the direction marked on the spool. Crossed windings are the other common reason line will not feed.
The blower intake and the air filter
A leaf blower pulls a huge volume of air, and the intake screen loads with leaf fragments, dust, and lawn debris.
Find the intake screen on the housing, usually behind a grill on the back or the side. Brush it clean and blow it out.
A clogged intake makes the blower feel weak and makes a gas engine run rich and hot. It is the first thing to check when performance drops.
The engine air filter is separate from the intake screen. On a gas unit, that is a foam or paper element under a cover near the carburetor.
Foam filters are usually washed in warm soapy water, squeezed dry, dried completely, and lightly oiled per the manual. Paper filters are tapped out or replaced, never washed.
A wet air filter is worse than a dirty one. Let it dry fully before it goes back in.
Cleaning the rest of the machine
Brush and blow the cooling fins on a gas engine. Packed grass on the fins causes overheating, and overheating is what kills two-stroke engines.
Wipe the housing with a barely damp cloth and a drop of dish soap, then dry it. Spray the cloth, never the machine.
Keep water away from the carburetor, the ignition, the switch, and any electronics. That is the same reasoning as in why power tools need compressed air, not water.
Do not pressure wash outdoor power equipment. High pressure drives water past seals into bearings, the air filter, and electrical connections.
Check the guard while everything is apart. The line-cutting blade on the guard edge keeps line at the right length, and a missing or dull one lets line run long and bog the engine.
Fuel, batteries, and storage
For gas units, fuel left sitting goes stale and gums the carburetor, which is the number one reason a trimmer will not start in spring.
Either run the tank dry before storage or use a fuel stabilizer, following the equipment manual.
Store fuel in an approved container, tightly closed, away from heat and ignition sources, and never in living space.
For battery units, store packs at moderate temperature and partial charge. Freezing garages and hot sheds both shorten pack life.
Store the machine hanging, off the floor, in a dry space. That protects the head, the shaft, and the guard from damage.
At the end of the season, do the whole yard fleet at once, including how to clean a lawn mower deck without getting hurt and how to clean, sharpen, and oil garden pruners and loppers. Our broader guide to cleaning outdoor gear, grills, and patio equipment covers everything else outside.
Habits that reduce the cleanup
Trim when the grass is dry. Wet grass is what packs and wraps.
Do not bury the head in heavy growth. Take thick material in passes from the top down rather than plowing through it.
Keep the line at the length the guard blade sets. Long line loads the engine and heats up, which is what fuses it in the spool.
Give the head a quick brush after each use. Thirty seconds then prevents the fifteen-minute job later.
FAQ
Why does my trimmer line keep breaking?
Usually because the line is old and brittle, because it is being run against hard surfaces like concrete and fences, or because the eyelets in the head are worn and shredding it. Replace line that has dried out, trim edges rather than grinding into hard surfaces, and check the eyelets for grooving.
Do I need to disconnect the spark plug on a string trimmer?
Yes, before removing the head, the spool, or any guard on a gas unit. Turning a cutting head can turn the engine, and an engine can fire on compression even when switched off. On a battery unit, remove the pack entirely rather than relying on the switch, and unplug a corded model at the wall.
Can I wash a leaf blower air filter?
Foam filters are usually washed in warm soapy water, squeezed out, dried completely, and lightly oiled per the manual. Paper filters are tapped out or replaced and must never be washed, since water destroys the media. Check your manual, since the wrong treatment on either type leaves the engine unprotected.
Why does my leaf blower feel weak?
Check the intake screen first, since leaf fragments and dust clog it quickly and choke the airflow. Then check the engine air filter, which is a separate part. On a gas unit, stale fuel and a partly gummed carburetor also cause weak, uneven performance, and that shows up most often after winter storage.
How do I get grass wrapped around the trimmer shaft?
Remove the spool, cut the packed wrap free with a utility knife without nicking the shaft, then pull the remainder off with pliers. Brush and blow out the head housing afterward. Wrapped grass under the head is the most common reason a trimmer stops feeding line, and it usually clears in a few minutes.
Should I pressure wash outdoor power equipment?
No. High pressure drives water past bearing seals, into the air filter, and into electrical connections, and the damage often shows up days later as corrosion rather than immediately. Brush the debris off, blow it out with compressed air, and use a barely damp cloth on the housing instead.
Yard equipment is one job and the house is another. If the second one needs attention, our house cleaning services can help. Every home is different, so the real number depends on size, condition, and what you want covered. Get a quote and we will walk you through it.