Generator throttle surging... governor?

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  #1  
Old 12-14-16, 05:08 AM
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Generator throttle surging... governor?

I have an old generator that has a techumseh 10hp motor. I cleaned the carb and put new gaskets in and the generaror came back to life. Except it is surging non stop and occasional back fire. I did notice if i spray the carb with carb cleaner, the engine bogs down once it hits the throttle shaft. Read this is somewhat normal.

Anyways what i also noticed was if i use my finger to gently stabalize the govenor/throttle linkage, the engine smooths out and runs perfect. Until i restart it. Is this a clear sign that the govenor is overly sensitive? There is a nut to tight the spring. In fact the engine runs great when take the govenor spring off and control throttle by hand.
 
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Old 12-14-16, 11:56 AM
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The spring adjustment for the governor adjusts engine speed, it needs to be set at the correct rpm or the voltage and hertz will be incorrect.

The carburetor is running borderline lean.
 
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Old 12-14-16, 02:12 PM
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Adjusting the mixture screw dosnt seem to make the surging go away. The main jet is clean clean clean. I ran a wire through it for a while. Is it possible the linkage on the govenor/throttle has to much slo or should be relocated to a different hole in the carb? Theres at least 5 holes for the throttle
 
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Old 12-14-16, 04:34 PM
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If the throttle shaft is badly worn letting air in, or some other part of the carb is restricted or other scenario might cause it to run lean. Does this one have the small brass jet screwed into the side of the carb or just a needle screw? How many holes did you clean in the main jet/bowl screw?
 
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Old 12-14-16, 06:16 PM
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Yes it has a needle in the side for idle mixture. The main jet screws into the bottom of the bowl and goes straight up. The jet has a hole going straight through horizontally. Then a much smaller hole going halfway throu horizontally. Does it make sense that the generator runs great without the govenor hooked up? Thank you so much for you help!
 
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Old 12-14-16, 07:02 PM
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Just fixe a Honda EU2000 with electronic governor by cleaning carb and then adding carb and injector cleaner to fuel tank and running it a few minutes. Engine settled down, quit hunting and backfiring. Voltage a steady 122.6V loaded or not.
You might try something similar.

RR
 
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Old 12-15-16, 07:58 AM
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The small horizontal holes near the base of the main jet is the path for gas at idle. When these hole openings get reduced by crud in the gas, the rpms drop at idle causing the governor to increase the throttle causing the gas path to change to an intermediate or high speed path. This increases the rpms. When the throttle returns to the idle position, the cycle repeats. Solution is to clean the main jet idle passages. Look carefully as the crud can sometimes camouflage the hole because they are so small. Hope this helps.
 
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Old 12-15-16, 08:46 AM
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When I service generators I take the carb to a small engine shop and have them clean it in their parts cleaning bath. Works every time.
 
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Old 12-15-16, 08:51 AM
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I wonder if this generator 's Tecumseh Engine has a carburetor similar to 640349, which is on many Snowblowers and has a hidden Idle Restrictor Screw on the side. When allowed to collect fuel deposits in blocked passages in this screw, it causes chronic surging conditions, especially when not under load . . . . which sounds very similar to the problems with the OP's Generator.

Here's a video showing the correction of this surging . . . . just in case it's the same kind of Tecumseh Carburetor:

https://www.youtube.com/watch?v=GT0STIPg4I8
 
  #10  
Old 12-16-16, 06:33 PM
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Is it normal tho that when i spray carb cleaner on the trottle shaft of the carb, the motor bogs down? I immediatly thought that was a problem. Ive always been taught to spray carbs on jeeps to find where they suck air.
 
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Old 12-16-16, 07:43 PM
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It should make minimal difference. Is there a lot of play side-to-side in the throttle shaft?
 
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