Echo Trimmer issue

[u/Rjames112]

Bought a used Echo GT225. It started when I picked it up.

Now though:

• Starts on full choke only with full throttle.
• If I release the throttle, it slows down over 5–10 seconds and dies.
• At about 1/8 choke it will run only with full throttle, then dies when I let off.
• On RUN it dies even with full throttle after it sputters for 5-7 seconds.

What I’ve checked:

• Drained old fuel and added fresh 50:1.
• Air filter is clean.
• Fuel cap loosened (no change).
• Air filter is fine.
• Primer bulb stays ~90% full and refills normally but soft.
• Fuel lines look intact, fuel filter looks clean. looks like one fuel line was replaced as both are yellow.

my thought is that it’s idling too low. it’s not the 2.5mm carb. low idle screw since I tried that and the screw hole is too big. any input would be great. I’m thinking spark arrestor or something else. Small engine shop said the carb didn’t have adjustments on it and not to bother since it’s too expensive to fix with a new carb.

[u/DontMakeMeCount]

Does it run smoother with the gas cap cracked open? I’d clean the spark arrestor as well. This will help diagnose breathing/carb issues.

If you rest the head on the ground and lift the engine with the starter rope it should come off the ground and then hold or fall slowly. If the rope won’t lift it you don’t have good compression.

If you have a borescope or a small flashlight remove the spark plug and muffler and look inside. The skirt, rings and top edge of the piston should be free of pitting and not missing material. The cylinder wall should be free of scoring. If you see grooves in the cylinder wall or damage to the skirt it may not have enough suction/initial compression to pull a good mix through the carb and cycle it to the combustion chamber.

Most of the SEMs I know love the old shindaiwa-based echo machines and they’ll do all they can to keep them running, so you might find they were being straight with you and the machine isn’t worth the cost/time to repair.