How often should you service your string trimmer?
Grumpty's answer
Every 12 months
Why bother
Stale fuel gums the carburetor and won't start come spring. A thorough-tier job. Skippable when life's busy, worth it when it isn't.
Why it's a range
Once a year, and the easy habit is to do it right before the season's first use. Heavy or dusty work, check the air filter every 90 days or so and the plug every three or four months; a 4-cycle engine wants its oil after the first 10 hours, then every 28. Light occasional use can stretch the in-season checks, which is why the annual service is the anchor.
What the job involves
- Clean or replace the air filter. Rinse a foam filter in soapy water and dry it; swap it if it's torn or clogged. While you're in there, pull the spark plug and replace it if it's blackened, fouled, or corroded.
- Run out or drain the old fuel and refill with fresh gas at the right mix. Most 2-stroke trimmers want 50:1 fuel to oil; a 4-cycle engine gets an oil change instead.
- Swap the fuel filter and look over the fuel lines and primer bulb for cracks. Reload fresh trimmer line if the spool's brittle or empty.
- Test-run it. If it's going away for winter, add fuel stabilizer or drain the system, so the carburetor doesn't gum up over the off-season.
Do it yourself, or pay someone?
Yourself, mostly. The air filter, spark plug, fresh fuel, line and fuel filter are all owner's-manual jobs needing basic hand tools. Hand it to a small-engine shop if you'd rather not fiddle, or if it already won't start: a full 2-stroke tune-up runs about $70 to $81, plug, air filter, carb clean and adjust, fuel filter and line, plus parts if the carburetor needs a rebuild.
What skipping it costs
$40 to $160 is what a shop charges to undo it, once the trimmer's sat on stale gas and the carburetor's gummed with varnish. The carb part is $40 to $50, the labor $48 to $90 an hour, and one real Husqvarna 128LD that wanted a carb, fuel lines, plug and filter came to $158. A DIY rebuild kit is only $15 to $25, but that's the price of doing it yourself, not the bill you skip. Fresh fuel and a splash of stabilizer at the end of the season is the cheap way out of all of it.
Signs it's overdue
- Hard to start, won't stay running, or stalls at idle. That's the classic gummed-carburetor sign from stale fuel.
- Loses power, bogs down, or runs rough under load, usually a clogged air filter or a fouled spark plug.
- The trimmer line snaps constantly or the spool's gone brittle, and there's black, sooty muck on the spark plug.
When to start thinking about it
A few days' warning does it. Grumpty grumbles 5 days out, then leaves you alone. Mark it done and Grumpty sets the next one, every 12 months, so you can go back to forgetting it exists.
Questions people ask
How often should you really service a string trimmer?
At least once a year, and the easiest habit is to tune it up right before the season's first use. In heavy or dusty work, check the air filter roughly every 90 days and the spark plug every three or four months; a 4-cycle engine wants an oil change after the first 10 hours, then every 28. Light, occasional use can stretch the in-season checks, which is why the annual service is the one that anchors the lot.
Why won't my trimmer start after sitting all winter?
Gas starts going off in as little as 30 days, and ethanol-blended fuel pulls in moisture and leaves varnish that clogs the carburetor's tiny jets, so it can't draw fuel. Drain the old fuel, refill with fresh gas, and replace the spark plug first ($5 to $10). If that doesn't do it, a carburetor rebuild kit ($15 to $25) usually clears it, or budget for a shop carb service. Next time, a splash of fuel stabilizer or draining the tank before storage saves the bother.
Do you have to drain the fuel before storing it?
Not necessarily. Either run the tank dry, drain it, then prime and run until it stalls to clear the carburetor, or add stabilizer to the last tank and run the engine two or three minutes so the stabilized fuel reaches the carb. Stabilizer keeps fuel usable for up to about 24 months. Either way, store the trimmer somewhere cool and dry.
Related jobs
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