Did I kill my string trimmer by running without the muffler? ?

My 2 cycle string trimmer has been running fine all season. Last job, it shut off after an hour of running. Spark good, intake good, removing muffler/spark arrestor got it going again.

Decided to finish up with no muffler and just order one for next time since it’s non-serviceable. Ran fine for 20 more minutes and stopped. Engine appears to be seized, pull cord is stuck and won’t turn manually with pull cord assembly removed.

Tanaka string trimmer, 7 years old. Same fuel to oil ratio as ever and have used the current mix for a few rounds, no issues. No other visible issues of fowling or plugging at muffler intake or exit. 

Did I cause the engine seize by running without muffler? Is this worth trying to resurrect, or time for a new one?

3 Answers

  • 2 months ago
    Favourite answer

    Removing the muffler and it ran good indicates a carb issue. There is likely a bit of debris at the jet causing the problem, or maybe it just needs to be slightly adjusted.

    Removing the muffler should not have caused the engine to seize.

    To try & free up the engine, try squirting penetrating oil into the cylinder, via the spark plug hole, and into the crankcase. Try and get to the crank & rod bearings & wrist pin. Put a vice-grip on the crankshaft and work it back & forth . It may take a while. Use plenty of penetrating oil.

    I also have a Hitachi (Tanaka) straight shaft string trimmer, and even though the manual says to use a 50/1 mixture, I do 40/1, just for the extra lube.

  • Anonymous
    2 months ago

    WRONG FORUM. You should be asking in the HOME & GARDEN category, not CARS & TRANSPORTATION. Fail

  • Bill
    Lv 6
    2 months ago

    Running without a muffler shouldn’t hurt anything except everyone’s ears. Disassemble it and see what failed, or buy a new one. 

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