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How do you make a honda gx240 generator quieter
bigbravedave - 19/9/11 at 09:23 PM

All ideas welcome, we've got a honda gx240 engine (240cc, single cylinder runs at 3000rpm) on a generator that is a bit noisey. As it sometimes gets run for long periods we'd like to quiet it down

so what do people reckon, I think it's mainly exhaust noise as its exhaust is about the size of a tub of butter. so was thinking of getting an exhaust off a 125cc commuter / moped. My question – If I went for a much bigger exhaust like off a Blade, would it be quieter because there’s more of it to absorb the noise, or louder as it’s designed to vent considerably more exhaust gas?



All input appreciated!


P ? - 19/9/11 at 10:38 PM

depending on size and budget... box it in with wood and insulation might be the way, works a tread with our noisey office printer ...

did something similar on a narrow boat in the engine bay. 3" insulation worked a treat to cut down on a landrovers thud


HowardB - 20/9/11 at 07:01 AM

may I suggest extreme care boxing it in, otherwise overheat is the likely outcome.

I would suggest that a simple one sided barrier might work, perhaps with some sort of foam on it, but even my the "silenced" gensets aren't that quiet. Mine is about 60db, an open frame one is about 70db.

Much depends on where you might be using it, fixed at home during power cuts, or in a public space?


wilkingj - 20/9/11 at 08:32 AM

When I was on BT, the generators and pumps had an extension pipe (short flexi pipe) with an additional silencer. This did work quite well. Although you might need to weld some sort of flange / suitable pipe / outlet to the existing silencer to be able to mate up the extension pipe. This would give you the best of both worlds, as its removeable.

Agree with the above, these are air cooled engines, and need good ventilation.

Also agree with a barrier, I am a radio Ham, and on competition weekends in a field, we just put up a camper windbreak, and it does make a small difference. You could use a denser material or that reflective heat sheet, use the shiny side towards the sound, it will reflect some of it back.

Also consider whats behind the genny, ie reflecting the sound back at you.

Bales of straw are good, if they are to hand, although watch out as they can be a fire hazard.

Have fun, and be safe.



[Edited on 20/9/2011 by wilkingj]


Confused but excited. - 20/9/11 at 01:37 PM

Run it in next door's gagage?


rusty nuts - 20/9/11 at 07:59 PM

Rubber mounts can quieten compressors , they may work with a generator?


Ivan - 20/9/11 at 08:16 PM

Lead the exhaust into the bottom of an open ended drum filled with 50mm stone.