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briggs overspeeding problem

Discussion in 'Mechanic and Repair' started by mopar4u, Jun 25, 2008.

  1. mopar4u

    mopar4u LawnSite Member
    Posts: 31

    briggs 11hp 253707 0206 vertical on a snapper rer

    The engine is overspeeding by quite a bit at wide open throttle. It is hitting 3600rpm at about half throttle, no load, rpm's increase more after that. I checked the governor calibration and it seems to be correct. With the governor arm at full throttle I loosened the nut and turned the brass internal arm all the way to the right. It was already all the way to the right.

    Got the correct 1" governor spring (looks exactly like the one on there) and installed it, bent the tab in. It is still overspeeding.

    Made sure the throttle plate in the carb is present and closing all the way and it is. It does move freely.

    Took the sump off to look at the governor and all the weights were present. The part of the governor that moves up and down moved freely. see attached photo

    The governor to carb link is free and has a new long spring attached to it.

    If you move the governor lever by hand the engine would speed up but it would pull back down to where it started. But sometimes when I would pull the governor lever by hand it seemed to slowly creep back down to where it should be or stall at the higher rpm for a few seconds then come back down. I didn't see anywhere it was binding.

    Any ideas?:dizzy: Thought I covered everything. If I can't get this thing running right it's going to small engine heaven *trucewhiteflag*

  2. mowermankevin

    mowermankevin LawnSite Senior Member
    Posts: 270

    Dang, sounds like you covered all the bases, are the governor weights moving in and out freely? If, with the engine cover off, spinning the governor by hand, make sure the weights move freely, something is binding and I don't know how to check for it with the engine case on. Possible that the engine case is warped? Look for unusual wear marks where the cam and cam bushing come together in the part of the engine case you took off. Maybe a shim is worn out or missing, but something is binding... Keep us posted, C'ya
  3. Partsangel

    Partsangel LawnSite Member
    Posts: 80

    I think you have it backwards?
    Loosen the 3/8 nut on gov arm again.
    When you push the throttle to full.. watch the direction of the gov arm..the internal shaft should be turned in that direction then held while tightening 3/8 nut. If that dosnt cure your prob then you might have the butterfly in your carb coming loose...very common and hard to diagnose.

    I hope this helps.

  4. xpnd

    xpnd LawnSite Senior Member
    Posts: 378

    Check your throttle shaft for wear. It should have very little movement left to right or up and down. You'll have to remove the linkage to check it.
  5. mopar4u

    mopar4u LawnSite Member
    Posts: 31

    maybe i did the calibration wrong. answer me this. after a proper calibration of the governor, with the engine off should the arm be touching the plunger (similar to the above photo) or not be touching the plunger?

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