Official McCulloch gas line trimmer parts

How to troubleshoot your McCulloch gas line trimmer when it runs rough

If the fuel has been in the tank unused for months, it can pick up moisture and fail to ignite (that's why you should drain the fuel before storing for the winter or add fuel stabilizer to the tank). Replace the fuel with fresh gas if it's old and untreated with stabilizer. You might also need to replace the fuel filter at the same time. Performing preventive maintenance including a line trimmer tune-up will also help the engine run smoothly.

Check the fuel lines for cracks and replace them if necessary. If you still have problems after checking those issues, consider replacing or rebuilding the carburetor.

What to do when your McCulloch 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).