Gas-fueled generator engine speed fluctuates, and refuses to run steadily

Discussion in 'Off Topic' started by Jeff7, Sep 20, 2004.

  1. Jeff7

    Jeff7 Lifer

    Joined:
    Jan 4, 2001
    Messages:
    41,589
    Likes Received:
    6
    We've got a gas-powered generator, about 2KW. It seems to work - sort of. The engine pulses though (for lack of a better word), which results in very uneven output. It'll rev up, slow down, and repeat the cycle, completeing a cycle like that in about 1.5 seconds. It doesn't sputter or choke or anything either, and it starts easily, usually on the first or second pull. The engine just won't run steadily - with or without a load on it.
    Does the thing need a new spark plug, some fuel injector cleaner, or something along those lines? It had Stabil in the gas that was in the tank, but that's all been used, and it's got new gas in it.
    Is the FIC for cars suitable for something like this?
     
  2. Analog

    Analog Lifer

    Joined:
    Jan 7, 2002
    Messages:
    12,755
    Likes Received:
    0
    Sounds like the governor spring is weak. The throttle has a spring that sets the 'control' for maintaining a certain speed at a certain load. If the spring is too loose, you will get that same result. I assume it has been sitting for a long time?
     
  3. Kalvin00

    Kalvin00 Lifer

    Joined:
    Jan 11, 2003
    Messages:
    12,705
    Likes Received:
    1
    Yep, something is amiss in the governor system.
     
  4. Jeff7

    Jeff7 Lifer

    Joined:
    Jan 4, 2001
    Messages:
    41,589
    Likes Received:
    6

    There was something that was springing back and forth, right in time with the engine speed fluctuations.

    Pic

    The green-highlighted part was what was springing back and forth.

    Yes, it had been sitting idle for several months at least.
     
  5. Lizardman

    Lizardman Golden Member

    Joined:
    Jul 23, 2001
    Messages:
    1,993
    Likes Received:
    0
    try moving the wire down a notch and see if that helps.
     
  6. Jeff7

    Jeff7 Lifer

    Joined:
    Jan 4, 2001
    Messages:
    41,589
    Likes Received:
    6
    Well it helped a bit. The thing has steadied its output considerably, but not entirely. The whole chassis still shakes, enough to make the entire generator move slowly in one direction, and the light I have attached to it does not shine consistently - it dims just a bit as the engine speed fluctuates. It's still not nearly as steady as a lawnmower engine is. Of course, I don't know really how steady your average generator is supposed to run, as this is the only generator I've ever seen.
    What about fuel injector cleaner? Is that safe for this kind of engine?

    Oh yeah, checked the oil level - it's ok.


    Update: I futzed around with the governor and that spring thing (or maybe that is the governor, I don't know), and now it's running almost completely steady. About every 20 seconds it'll slow down and shudder slightly, but other than that, the light I hooked to it stays quite steady. It would appear that this thing is ready for some action.

    Thank you to everyone who helped here. I'm never really one to mess around with gas engines. Computers are simple to me. DC current - don't short anything out. Engines - they all look like things Rube Goldberg came up with in his worst nightmares. And they come with a tank of flammable, volitile liquid strapped to them.
     
  7. Analog

    Analog Lifer

    Joined:
    Jan 7, 2002
    Messages:
    12,755
    Likes Received:
    0
    Glad to hear you're up and running :):)
     
  8. Tremulant

    Tremulant Diamond Member

    Joined:
    Jul 2, 2004
    Messages:
    4,890
    Likes Received:
    0
    flux-capacitor?