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Discussion Starter · #1 ·
Hello,

I have a briggs and stratton 5500 watt generator that's about ten years old. It was left at my dad's house for years and eventually the engine seized. I found a great deal on a new briggs engine on ebay and had a friend install it. Direct bolt on and runs great. The problem is that I don't think the governor is working right. At idle I noticed it was producing only 105 volts so I adjusted the idle to bring it up to 120 volts. But when I plug in a work light and a shop vac, the engine boggs down instead of spending up. I can't detect movement when looking at the throttle lever. Did I do something wrong? Maybe there's a governor problem, but the engine is brand spanking new. Any advice would be appreciated! Thanks!
 

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Welcome to the forum.

When you say you adjusted the idle, how did you adjust it? There should be an adjustment on the throttle control that you turn to bring the governed speed up - not the idle.

Can you post a picture of the carb and what you adjusted?
 

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Discussion Starter · #3 ·
Thanks for the reply aandpdan. I'll take a pic tomorrow when I can go back in the garage. There's a small adjustment screw on the throttle where it connects to the carb. I think it's the idle adjustment screw right?
 

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At the carb sounds like the idle screw. It's NOT what you want to adjust.

There should be another adjustment for the throttle assembly. Moving that screw will increase/decrease tension on the governor spring only.
 

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Discussion Starter · #5 ·
I see. Yes I'm pretty sure it was the idle screw that I adjusted. My thinking was that the gen should be giving out 120 volts at idle with no load, prompting me to adjust it. Should I adjust the idle back where it was and focus on the screw by the governor spring at the other end? Thanks again.
 

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Does your generator have an auto-throttle? Most portables don't. They run at around 3600 rpm ALL the time.

In that case you don't touch the idle screw at all. It will never idle. Focus on the screw by the governor spring. Putting more tension on the spring will increase the RPM and bring up the volts. If the spring is of the proper tension the engine will hold that speed fairly well as the loads change.

It's best to set the governor by hertz. You can use a kil-o-watt meter or some multimeters. Usually it's set at about 63 hertz no load so that as the loads increase it comes to about 60.
 

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Discussion Starter · #7 ·
My cheapo multimeter won't measure frequency, I'll stop by the hardware store and get one--good feature to have. Maybe I'm not using the correct terminology, but I know that the throttle is controlled by the engine itself. There's a rod that connects the throttle at the carb to an area on the other side of the engine, where there's some sort of probe that goes into the engine. My buddy says it has "paddles" on it that will cause it to move according to engine load, thus regulating it own throttle. It does have that tension spring that you speak of. I would expect that as I attach devices and draw power from the generator, the engine would speed up instead of slow down.
 

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That's the governor you're talking about with the paddles.

The RPM should hold almost constant, regardless of the load you put on it. The generator needs to run at 3600 rpm for 60 hertz (US). Yes it will vary slightly but it shouldn't speed up or down much at all.
 

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Discussion Starter · #9 ·
Thanks for the clarification, aandpdan. I think gave a grip on what's going on now. It seems that I need to adjust the governor to give me the correct frequency with load and no load (close to 60 hz I believe) and keeping steady RPMs. But first I probably need to undo what I did in the beginning, where I adjusted the screw on the throttle arm on the carb, as I'm not sure what it's for exactly.
 

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The carburetor is not specific to a generator - usually. It can be used on some applications, like a mower, that would idle. Hence the idle stop.
 

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Discussion Starter · #11 ·
OK so I hooked up my new multimeter and adjusted the governor to achieve approx. 63 hz with no load, but at that speed it's outputting around 150 volts. That voltage is way too high right? My oscillating fan and shop vac don't seem to mind, but I'm sure there's other equipment that would. Is this indicative of another issue? Thanks!
 

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Discussion Starter · #13 ·
It does drop but only slightly. I seem to be getting around 120 v at around 50 hz. Which would be ok in Europe I think. Is there another voltage adjustment somewhere? Perhaps on the gen head?
 

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The 50 hz would be OK in Europe but not the 120. They use 230.

Try your shop vac on it and measure the voltage. It needs some load to regulate properly. You may have a bad voltage regulator, if equipped.
 

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Discussion Starter · #15 ·
So I finally have the generator producing the output that I'm comfortable with. Making the adjustments by turning the governor shaft alone was producing wild fluctuations in the engine RPM. 50 hz at no load was as close as I could get it running by turning the shaft, any movement to speed up the engine would make it race like crazy and I had to shut it down immediately. But I was able to get it up to 60 hz/129 v by moving the governor spring two holes higher (they're numbered). When I attach a load to the generator, like a 1500 watt heater, the governor maintains the correct frequency and the voltage comes down slightly to an even better range. Seems to be running great now! Thanks for your help aandpdan!
 
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