Gas Line Trimmer: Won't start

The engine needs gas, compression and spark in order to start. First, make sure there's fresh gas in the tank-old gas accumulates water and burns poorly. Replace the fuel if it's old. Add fuel stabilizer to the gas when you refill the tank to help keep the fuel fresh.

If the fuel is fresh, check the fuel lines for cracks. Air enters the carburetor instead of fuel when the fuel lines have cracks. Replace the fuel lines if you find cracks in the lines. If the fuel lines are okay, you may need to rebuild or replace the carburetor because a dirty carburetor won't supply the engine with fuel.

Next, disconnect the spark plug wire and remove the spark plug. If you see deposits or corrosion on the electrodes, replace the spark plug.

Finally, to check for compression, remove the spark plug, press your thumb over the opening and pull the starter cord. If you don't feel air pushing from the cylinder, it's likely that the piston rings need to be replaced (for an accurate compression reading, use a compression gauge).

gas line trimmer

These repairs may help solve your gas line trimmer problem

Rebuild the grass line trimmer carburetor

Rebuild the grass line trimmer carburetor

Rebuild kits are available for most carburetors. The kit contains essential components for rebuilding a carburetor, such as diaphragms, seals and gaskets. You can sometimes fix a fuel supply problem by dismantling and cleaning a carburetor. Use the kit to rebuild the carburetor after cleaning it.

October 1, 2013
By Lyle Weischwill
How to rebuild a line trimmer carburetor

A line trimmer that's difficult to start could have a carburetor that's ready for a rebuild. This DIY repair guide shows you how to rebuild it yourself.

Repair difficulty
Time required
 30 minutes or less
Read more
Replace the grass line trimmer carburetor

Replace the grass line trimmer carburetor

The carburetor mixes air and gasoline in the proper proportions to create a combustible gas. If the engine starts and then sputters, or doesn't start at all due to lack of fuel, you might need to replace carburetor. It's often more cost effective and practical to replace the carburetor rather than rebuild it.

October 1, 2013
By Lyle Weischwill
How to replace a line trimmer carburetor

If your line trimmer is hard to start or just plain won't start, the carburetor could gummed up, or its gaskets could be shot. You can replace the carburetor yourself, in less than 30 minutes. Just follow these steps.

Repair difficulty
Time required
 30 minutes or less
Read more
Replace the grass line trimmer fuel lines

Replace the grass line trimmer fuel lines

Fuel lines become brittle over time and can crack or tear. Replace a fuel line that's brittle or damaged. Be careful to install new fuel lines on the engine the same way the original fuel lines were configured.

October 1, 2013
By Lyle Weischwill
How to replace a line trimmer fuel line

If your line trimmer won't start even though it's filled with gas, a split or blocked fuel line could be keeping gas from reaching the engine. This DIY repair guide explains how to replace line trimmer fuel lines in about 30 minutes.

Repair difficulty
Time required
 30 minutes or less
Read more
Symptoms for gas line trimmers

Choose a symptom to see related grass line trimmer repairs.

Main causes: stale fuel, clogged fuel filter, faulty spark plug, clogged air filter, cracked fuel lines, clogged carburetor
Main causes: stale fuel, cracked fuel lines, dirty carburetor, bad spark plug, worn piston rings
Main causes: cracked fuel lines, bad carburetor seals, leaky fuel tank cap, damaged fuel tank
Repair guides for gas line trimmers

These step-by-step repair guides will help you safely fix what’s broken on your grass line trimmer.

October 1, 2013
By Lyle Weischwill
How to replace a line trimmer carburetor

If the line trimmer won't start even though there's fuel in the tank, the carburetor could be the problem. Follow these instructions to replace the carburetor in under 30 minutes.

Repair difficulty
Time required
 30 minutes or less
October 1, 2013
By Lyle Weischwill
How to rebuild a line trimmer carburetor

If the line trimmer engine won't start even though there's fuel in the tank, the carburetor could be the problem. Follow these instructions to do the job in under 30 minutes.

Repair difficulty
Time required
 30 minutes or less
October 1, 2013
By Lyle Weischwill
How to replace a line trimmer fuel line

The fuel line on a grass line trimmer deteriorates with time and eventually can split or crack. You can replace it yourself, following these instructions.

Repair difficulty
Time required
 30 minutes or less
Articles and videos for gas line trimmers

Use the advice and tips in these articles and videos to get the most out of your grass line trimmer.

June 1, 2015
How to tune up a grass line trimmer video
By Sears PartsDirect staff

Tune of your grass line trimmer, following the steps in this video.

June 1, 2015
How to replace a line trimmer fuel line video
By Sears PartsDirect staff

Follow the steps in this video to replace a leaking fuel line in a line trimmer.

March 1, 2015
Grass line trimmer common questions
By Sears PartsDirect staff

From what kind of fuel to use to why your gas line trimmer won't start, here are the questions our experts hear most often about grass line trimmers.