1. Missed the live Ask the Expert event?
    Catch up on the conversation about fertilization strategies for success with the experts at Koch Turf & Ornamental in the Fertilizer Application forum.

    Dismiss Notice

14.5 HP I/C OHV Idles Fast, Runs WAY too fast

Discussion in 'Mechanic and Repair' started by Rain Man av, Apr 19, 2008.

  1. Rain Man av

    Rain Man av LawnSite Member
    Messages: 133

    B&S 287707, 0224. I recently took the carb off and cleaned and installed new seat / needle. I've taken carbs off before and cleaned overhauled. I believe all linkage is back to where it should be.

    Throttle moves well and easily, manual choke moves well and easily. When idling, engine seems to be running fast, when I increase speed, engine revs way too high for my liking. The only way to adjust speed is to choke it down. But then it runs like dog-poo.

    If the deck is engaged the RPMs drop and the mower engine speed at full throttle, sounds about right. If I disengage the deck, the engine REVs take off. I thought maybe an idle adjustment screw or fast adjustment screw needed attention, adjusting them had no affect what so ever.

    I did some research about this problem and found some reads that possibly the governor needs adjusting.

    Anything to point me in the right direction. Also, is there a way to tell if the governor is my problem ? I've never had to adjust a governor before. So be easy with me, it will be my first time.

  2. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    Well Rain Man,

    I can't be any easier on you than posting the governor adjustment procedure straight from the Briggs service manual;

  3. Rain Man av

    Rain Man av LawnSite Member
    Messages: 133

    Thanks for the information - it doesn't sound like it is going to hurt too much.

    If I read this right, I should be able to move the governor manually and the result would be that the engine revs would decrease. To adjust the governor permanently, I would have to follow the steps as indicated.

    I also assume that since you gave me the directions on how to adjust the governor, that this is the problem with the mower.
  4. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    Yes that is the permanent adjustment for the governor which is performed with the engine not running.

    The fact that all you did is remove the carb for cleaning leads me to believe that you may have pulled on the throttle linkage while removing the carb and moved the governor arm on the governor shaft.

    I have seen this happen in the past so adjusting the governor would be the first step in isolating the over-rev problem.
  5. Rain Man av

    Rain Man av LawnSite Member
    Messages: 133

    My governor does not move in response to moving the throttle. The spring between the throttle and governor is connected. I can manually move the governor, so I know it is not stuck.

    If I manually move the governor forward, then move the throttle to full, the governor will "snap" back (move away) from the carb, otherwise the governor does not move irregardless of how many times I move the throttle back and forth between full and slow.

    Should the governor move in response to changes in throttle position?


    FIXDISS LawnSite Senior Member
    Messages: 445

    If you adjusted the governor as posted by Restrorob then it is adjusted correctly. Is the rod from the top of the governor arm connected to the throttle on carb ? When you push the governor lever toward the carb the throttle should open all the way.When you release it it may return slightly toward closed. When you push the throttle cable toward fast or choke you are actually only increasing the tension on a spring that controls the governor.
  7. Restrorob

    Restrorob LawnSite Fanatic
    Messages: 11,029

    Yes, If you have the engine running at idle then grab the throttle control and snatch it to full throttle as fast as you can the RPM will spike a little above the preset RPM then settle back to the preset RPM.

    If you snatch the throttle and the RPM's skyrocket and stay that high there is a problem with the governor. That's where the adjustment procedure I posted comes into play.

    If the adjustment has no effect and RPM's still skyrocket the governor may have slung apart inside the engine.

    Gotcha now, The governor will not respond to throttle movement unless the engine is running.
  8. Rain Man av

    Rain Man av LawnSite Member
    Messages: 133

    I found the problem.....

    The rod between the governor and the throttle plate on the carb was bent. I must have bent it when I was putting the carb back on after the cleaning. The bent rod was actually rubbing up against the side of the engine - impeding it's movement and the bent rod shortened the distance between the governor and the throttle plate, effectively opening the throttle and causing the RPMs to be excessive.

    I straightened the rod and now the engine runs normally. Took the mower out for a test mow, and she performed flawlessly.

    Thanks for all your help. I'll be sure to keep this post handy should I ever need information on how to adjust the governor.

    PS. The reason for cleaning the carb was a flooding issue. I replaced the seat and needle but still flooding. The problem is that when you turn the carb over, the float dips past level. When I got the mower it had a shut off valve in the fuel line. I had hoped to correct the problem at the carb, but had no luck, reinstalled the shut off. Fuel in the oil made her run smokey, so I changed the oil and the problem went away. The fact that gas in the oil will make a perfectly good mower run smoky, is info I learned from this forum, different thread.

    again, thanks for all your help.

    Rain Man.

Share This Page