What causes engine surging?

Discussion in 'Mechanic and Repair' started by Okiebug003, Oct 3, 2009.

  1. Okiebug003

    Okiebug003 LawnSite Senior Member
    Messages: 250

    I have a Cub Tank M54 with a Kaw 23 hp engine. The engine started surging yesterday at both low throttle and high throttle. I changed out the fuel filter, no difference. Once i engage the blades it seems to go away. Anyone have any ideas? thanks
  2. DT Lawn Care

    DT Lawn Care LawnSite Senior Member
    Messages: 850

    Clean out your carburetor, or at least try running SeaFoam or other good additive through it, should fix your problem. Also maybe check to make sure your choke butterfly is opening and closing properly, I had a butterfly bust and it was just fluttering around, causing surging and problems. Good Luck
  3. carriedrewdog

    carriedrewdog LawnSite Member
    Messages: 68

    Could be dirty gov linkage, but probably not. Most surging is caused by a lean mixture. In addition to carb problems (before you rip off and dive into the carb) check for a loose carb mount and leaking gaskets. I always check and eliminate the easy stuff first, once in a great while it works.
  4. Cboy7

    Cboy7 LawnSite Senior Member
    from Fl
    Messages: 386

    yea check carb 1st , maybe a spring jumped off, or the idle is set too low.

    i did that just last week, set the idle screw too low , and it would surge down and almost die before coming back up
  5. statman

    statman LawnSite Senior Member
    Messages: 268

    i have a exmark lazer with a 23 kohler. when it surged and then started losing power, the mechanic said it seeded a new carb. I tried to rebuild. $150 later I put on new carb and the problem went away.
  6. dwost

    dwost LawnSite Bronze Member
    Messages: 1,667

    Hi all, I'm having a similar issue on a new Briggs Vanguard 9hp motor on my powerwasher. Hoping someone can help me out. I bought it last year and it worked fine for the first 4 or 5 times and then it started acting up. Well,I pulled it out of storage and did the routine maintenance on it. Changed oil, new fuel, replaced oil in the pump, plug, etc... I ran it for a few minutes and seemed to work fine. I decided since it warmed up that I'd wash off our back deck and patio so I went at it. Started right up and I began working. About 3 minutes in once it warmed up it started surging and it eventually died. Had to rechoke it and it would continue to do the same thing. I looked at everything, adjusted what I could and it didn't help. The weird thing is it runs fine at idle but when I throttle up it just bogs and dies. The mixture adjustment has a stop on it so I have limited adjustment. I'm wondering if its something internal? I may just call Briggs since it's under warranty but would rather just fix it myself. Before I tear into pulling the carb any recommendations on other things to check?

    FIXDISS LawnSite Senior Member
    Messages: 445

    Remove the bolt from bottom of the bowl on carb and catch into a small container.(A paint can cap works well,preferably a white one so you can see what comes out).You may have a little water in the bowl causing the surge and eventually stopping the fuel flow and making it die.
  8. dwost

    dwost LawnSite Bronze Member
    Messages: 1,667

    Just drained it and it looked like there was no water. There was, however, some very small particulate so there is a chance it may be clogged. I've sprayed it liberally with carb cleaner and will let it sit overnight. I'll hit it again in the am and fire it up. I may just pull it apart and give it a good cleaning. I think there was some residual fuel left in it over winter which means it may be varnished. I'll report back once I give it another go.
  9. topsites

    topsites LawnSite Fanatic
    Messages: 21,653

    Yeah, usually a dirty carb ...
    Have to clean all that up real good, inside and out, linkages and all.

    Some piece that's broken or worn on the governor linkage.
    Still have to clean it if you want to see clearly :p
  10. Merkava_4

    Merkava_4 LawnSite Bronze Member
    Messages: 1,443

    I can't stand an engine that surges or sputters.

    Listening to my neighbor's mower is sheer torture at times. :cry:

    People just need to learn how carburetors work and how to clean them.

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