How to Repair Your Weed Eater Mower

Almost all weed eater mowers operate on a two-cycle gas-powered engine. These engines have been designed to only need three basic things to start: spark, fuel and compression. To make any repairs to the engines you should first diagnose the problem into one of these three areas. That way, you can fix all of the parts in that system that could be malfunctioning, rather than fixing a part you think is bad, only to find out it's just a symptom of a larger problem.

Screwdriver

Socket wrench

Spark plug

Wire brush

Rag

Starter fluid

Use the screwdriver to slide off the spark plug's rubber boot attachment. Use the socket wrench to unscrew and remove the spark plug. Replace it with a new one.

Set the new spark plug in place inside the rubber plug, but don't attach it to the engine. Let it sit close to a metal point on the engine block to ground the electrical connection.

Tug on the starter cable, and look for a spark across the spark plug and metal part. If there's no spark or it's weak, check the plug attachment and cable for any damage. Replace if necessary.

Unscrew the handle and throttle from the engine. Check the ignition wires leading up to the "On/Off" switch for any damage. Replace wires as necessary to make the circuit complete again.

Test the starter coil and magneto gap to make sure they can still hold the proper charge. Remove and replace the flywheel key if the spark is weak or the timing is off. Take it to a mechanic if the problem still persists.

Use the screwdriver to remove the air filter and muffler covers. Take out the air filter and spark arrestor screen (inside the muffler).

Clean both with warm, soapy water and a metal brush. Allow them to dry overnight before putting them in the engine.

Examine the muffler for any holes or cracks on the outside. Inspect inside the muffler for any airflow blockages or damage. Make sure the muffler is securely fastened or welded to the engine.

Remove the muffler from the engine, and thoroughly inspect the bore, cylinder and piston for any cracks or damage if the problem still persists. Take it to a small engine mechanic for further testing of the cylinder, piston seals and rings if there's no damage.

Empty any old fuel left in the tank into an approved fuel container. Mix gas at a 40:1 fuel-to-oil ratio into another fuel container; fill the tank with fresh gas. Try starting the engine.

Put the new fuel back into the freshly mixed container. Inspect the fuel tank for dirt, grass or debris that may be blocking the fuel filter or fuel line. Clean the inside with the brush and rag.

Remove the old fuel line and fuel filter from the engine if the problem still persists. Replace with new parts, refill the tank and try starting the engine again.

Set the choke lever to half-open. Access the carburetor's neck, usually found near the air filter, and spray a little starter fluid into the open neck. Try starting the engine. If the engine smokes and dies or won't start at all, you're carburetor is dirty.

Take it to a mechanic who can remove, disassemble and clean your entire carburetor. Reinstall the carburetor with a carb kit.