Surging

Discussion in 'Mechanic and Repair' started by vipermanz, Dec 27, 2001.

  1. vipermanz

    vipermanz LawnSite Bronze Member
    Posts: 1,773

    i have a 4hp briggs that seems hellbent on surging up and down.

    i've: changed gas, spark plug, air filter, and still no change.

    i request the help of some one else.
    :( :confused: :(
     
  2. Turfdude

    Turfdude LawnSite Bronze Member
    Posts: 1,900

    Check/clean /replace fuel filter?? Maybe a small hol in gas line somewhere, look at a few other smple solutions.

    Bob
     
  3. Remo Sid

    Remo Sid LawnSite Member
    from USA
    Posts: 55

    I have saw this problem addressed in several different forums, and have did a lot of research. Although some swear by certain remedies none seem to work with all engines. I have sometimes adjusted the carb a little richer and helped some, but with that you are just robbing Peter to pay Paul. Some sugest the Gouernor spring is oscilating; I do see how that could cause it, but it is not the problem with all that does it. I believe it is the newer carbs. In 1997 the govt. mandated emmission control standards the manufacturers had to meet. This surging is a tradoff for cleaner emmissions. Some carbs on the market now are un-adjustable. It looks like we will just have to live with it.:mad:
     
  4. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    There you go. My grandfather's Toro push mower did that recently. I adjusted the carburator and it helped out a lot. Try that.
     
  5. vipermanz

    vipermanz LawnSite Bronze Member
    Posts: 1,773

    it's definetly a governer problem, i can push it one way and hold it there and it runs fine, push it another way and it trys to quit (butterfly closes), i don't think it has anything to do with the carb (it's a diaphragm style:( ) that draws straight from the tank:confused: :confused:
     
  6. sdwally

    sdwally LawnSite Senior Member
    Posts: 385

    Surging can be cause by a few different things.
    1. Carb jet partially plug, not getting the right fuel mixture. Bad carb diaphragm and or pickup tubes(gas tank mounted to carb, no fuel line).
    2. Governor out of of adjustment. On the governor arm at the end where the governor shaft goes into the engine, loosen the arm and push the arm to full throttle. Rotate the shaft in the same direction as to cause the arm to open the carb to full throttle. Retighten arm to shaft.
    3. Loose carb or intake components and or bad gaskets. Sucking air to cause wrong air/fuel mixture.

    Governor spring will not cause this problem, it will only affect top end speed of engine.
     
  7. Robert Doubrava

    Robert Doubrava LawnSite Senior Member
    Posts: 342

    Oh. I'm familiar with the old fashioned type carbs.How old is the engine? If it is not older than about 5 years, then that is pretty odd that that engine is doing that. It's a B&S Quattro, right?
     
  8. vipermanz

    vipermanz LawnSite Bronze Member
    Posts: 1,773

    you got, it 2-3 years old
     
  9. Remo Sid

    Remo Sid LawnSite Member
    from USA
    Posts: 55

    This problem is not caused by the governor adjustment. ( Do not) mess with the governor adjustment unless you are very competent in this area. You will end up with more problems than surging.

    If you will think for a minute, the engines referred to here that have surging problems ( do not ) have an adjustable governor. The type engine you referr to with the adjustable ( mechanical ) gov. very seldom have surging problems, and when they do they respond well to making carb settings richer.

    The last thing a novice wants to do is mess with the gov. setting.:angel:
     
  10. vipermanz

    vipermanz LawnSite Bronze Member
    Posts: 1,773

    i'll take it off tomorrow and see if anthing is up in the vane or around it maybe it got chipped:confused:
     

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