# Honda GX340 generator vibrates bad



## snowball (May 3, 2005)

Hi, been a while since I needed your help. I have a Honda gx 340 on a 6000 watt dewalt generator that vibrates *violently* when running.It won't rev up at all to the correct rpms, but the throttle plate inside the carb is wide open. Moving the gov leakage back and forth while engine is running makes no difference to raising the rpms. It's almost like a counter weight is off the crank. You can hardly hold the generator because of the vibration. Any ideas what could be causing this. I've ultrasonic cleaned the carb, cleaned tank, fresh gas,checked valves, replaced plug, checked engine mounts. What am I missing?


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## snowball (May 3, 2005)

MY, MY, almost 70 hits here and nobody's come across this kind of problem or has any idea what I can do to fix this hey. I do get the dandy ones to repair at times. I guess I'll have to get another carb and totally eliminate this from the list.


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## 30yearTech (Sep 14, 2006)

While I have never run across this on a generator, I have had engines that vibrated, mostly due either to a bad counter weight or an out of balance attachment. 

The carburetor is not likely the cause of the vibration.


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## tezoost (Feb 13, 2015)

I need to know what to set the idle speed and the high speed RPM on the carb.I think the high speed is to high with no load on the engine.The model# HM100 Spec #159353P 10HP,It has a Comet pump on it.I do have a tach meter to set the RPM's.I have not check the rpm as of yet.I shut it down,soon has I got it running,it sounded to fast.Ididn't want to throw a rod,


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## 30yearTech (Sep 14, 2006)

tezoost said:


> I need to know what to set the idle speed and the high speed RPM on the carb.I think the high speed is to high with no load on the engine.The model# HM100 Spec #159353P 10HP,It has a Comet pump on it.I do have a tach meter to set the RPM's.I have not check the rpm as of yet.I shut it down,soon has I got it running,it sounded to fast.Ididn't want to throw a rod,
> 
> 
> _________________________
> sjh3


Rule of thumb for most engines is 3000 to 3400 rpm. Usually the attachment dictates engine speed. 

Engines on generators are usually set at 3600 rpm to develop 60 cycles of power output, but that does not apply to inverter type Gensets.


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## doni90 (Feb 18, 2015)

sorry, i don't know


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## billsmowers (Mar 21, 2008)

snowball said:


> Hi, been a while since I needed your help. I have a Honda gx 340 on a 6000 watt dewalt generator that vibrates *violently* when running.It won't rev up at all to the correct rpms, but the throttle plate inside the carb is wide open. Moving the gov leakage back and forth while engine is running makes no difference to raising the rpms. It's almost like a counter weight is off the crank. You can hardly hold the generator because of the vibration. Any ideas what could be causing this. I've ultrasonic cleaned the carb, cleaned tank, fresh gas,checked valves, replaced plug, checked engine mounts. What am I missing?


this may not be a engine problem it sounds like you have a short in the alternator causing the engine to load up like in this video
https://www.youtube.com/watch?v=jWDAZBD0FFM#t=13

the fault was not the engine but a short in the alternator


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## Sir Thomas (Dec 7, 2013)

snowball said:


> Hi, been a while since I needed your help. I have a Honda gx 340 on a 6000 watt dewalt generator that vibrates *violently* when running.It won't rev up at all to the correct rpms, but the throttle plate inside the carb is wide open. Moving the gov leakage back and forth while engine is running makes no difference to raising the rpms. It's almost like a counter weight is off the crank. You can hardly hold the generator because of the vibration. Any ideas what could be causing this. I've ultrasonic cleaned the carb, cleaned tank, fresh gas,checked valves, replaced plug, checked engine mounts. What am I missing?


Have you run the motor separate from the generator. Could be the timing is a little off. Check your flywheel key. It's not an expert opinion. Just a thought.


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