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Portable generator won't put out electricity

Not You

Well-Known Member
Joined
Feb 21, 2014
Messages
66
Location
USA
4,000 watt portable generator w/ Honda engine. The engine runs fine. When it was last used in the spring, everything worked fine. Now, it won't put out electricity. Checked the breakers and they seem fine. What are some easy things to check?
 

Birken Vogt

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Joined
Nov 30, 2003
Messages
5,305
Location
Grass Valley, Ca
Most non-Honda portables, Honda engine or not, are pretty much junk.

If you check the output voltage with it running you may find 5-10 volts AC. Then you have a reasonable suspicion that the copper is OK.

Then it is usually the voltage regulator if it has one, or if it doesn't it will be the capacitor or rotating diodes. Sometimes it is the brush holder. Tear off the generator end cover and see what you have.
 

doublewide

Senior Member
Joined
May 31, 2015
Messages
844
Location
MA
Have a 5000 watt Honda generator w/ honda engine. Went to use it one day and nothing! Fired up just fine, circuit breaker was good, couldn't figure it out. Took it to the tool repair shop. They took the cover off the generator? and cleaned up the end of the armature? with an eraser? while it was running. You know, the spinny roundy thing that the brushes make contact with. Had gotten a bit oxidized and wasn't making good contact with the brushes. Sorry, it's been a long time.
 

Birken Vogt

Charter Member
Joined
Nov 30, 2003
Messages
5,305
Location
Grass Valley, Ca
They took the cover off the generator? and cleaned up the end of the armature? with an eraser? while it was running. You know, the spinny roundy thing that the brushes make contact with. Had gotten a bit oxidized and wasn't making good contact with the brushes. Sorry, it's been a long time.

That can work but it has to be pretty oxidized for that to happen. Usually after it has been sitting for many years.
 

ol'stonebreaker

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Apr 26, 2015
Messages
333
Location
Idaho
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retired
While it's running plug a drill into it and,while holding the trigger in and by hand, spin the drill backward. Some gennies have capacitors to store exciter voltage and they tend to bleed off over time. The drill motor with magnetic fields will kick out enough voltage to get the exciters working.
Mike
 

thepumpguysc

Senior Member
Joined
Mar 18, 2010
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7,445
Location
Sunny South Carolina
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Master Inj.Pump rebuilder
There are some EXCELLENT videos on utube on how to check them, what the voltage/ohms should be and how to repair & replace the part.
and IF its not worth repairing..
 

Not You

Well-Known Member
Joined
Feb 21, 2014
Messages
66
Location
USA
Update - I did as ol'stonebreaker and YouTube said and it actually worked. The drill ran slowly at first, but gradually picked up speed.
 

ol'stonebreaker

Senior Member
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Apr 26, 2015
Messages
333
Location
Idaho
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retired
Glad to help and made it an easy fix. It doesn't work on 100% of them, but it is an easy thing to do before tearing into it.
Mike
 

Not You

Well-Known Member
Joined
Feb 21, 2014
Messages
66
Location
USA
I let the generator sit for a few days and tried it again and the drill wouldn't spin. I did the same flash procedure and it worked again. The drill would start spinning slowly and after a few trigger pulls it would spin faster. Does that mean the capacitor is bad? I am only assuming that it has one, I haven't taken it apart.
 

AllDodge

Senior Member
Joined
Apr 2, 2011
Messages
2,287
Location
Kentucky
My guess is you have either a diode or capacitor which has gone bad, more so on the cap. The gen needs to produce a DC voltage to excite the windings. Going to need to take it apart
 

thepumpguysc

Senior Member
Joined
Mar 18, 2010
Messages
7,445
Location
Sunny South Carolina
Occupation
Master Inj.Pump rebuilder
Like I said in post #6.. theres a guy on utube that shows you EXACTLY what to check & how to check it..
All you need is a screwdriver & a volt meter..
 
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