Symptoms
- Exhaust note is noticeably louder or has a different tone
- Rattling or buzzing sound from body panels
- Loud whine that wasn't there before
- Noise increases specifically under load
Likely causes
- CommonDamaged, loose, or missing mufflerA muffler that's rusted through, cracked, or has come loose will noticeably increase exhaust noise.
- CommonLoose exterior panels or covers vibratingFasteners can work loose with use and vibrate audibly against the frame.
- PossibleEngine running at higher-than-normal speedA governor issue can cause the engine to run faster than intended, which is both louder and produces off-spec voltage.
- PossibleWorn engine bearings or internal partsMechanical wear can introduce new noises not present when the unit was newer.
What to do
- Inspect the muffler and exhaust system for visible rust-through, cracks, or looseness at its mounting points.
- Tighten or replace a damaged muffler, since this is a common and relatively simple fix.
- Check all exterior panels and covers for loose fasteners and tighten them.
- Compare the engine's running sound and speed to when it was new or to the manual's spec; a noticeably higher-pitched engine note may mean it's running too fast.
- If speed seems too high, have the governor checked and adjusted, since this also affects output voltage.
- Listen closely under load versus no load to help distinguish an exhaust/panel issue (usually similar in both) from an engine-load issue.
- If noise seems to come from deep inside the engine itself rather than the exhaust or panels, have a small-engine shop inspect it for internal wear.
Tools and parts
- Wrench set
Generator muffler/exhaustSearch: “generator replacement muffler”
When to call a pro
If tightening panels and checking the muffler doesn't quiet things down, and the noise seems to come from inside the engine, have it checked by a small-engine shop.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.