25 horse mercury bog

Discussion in 'Bubba's Outboards' started by gearhead, Mar 11, 2007.

  1. gearhead

    gearhead New Member

    Messages:
    274
    State:
    China Grove, NC
    I have a 25 horse mecury i run every saturday ,it picked up a slight bog on take off and will cut off ,i can pull the primer fire it back up and ease off , i use to just gun it and it was fine , i installed new plugs dumped the fuel tank drained the filter cup had no trash in it ,i allways use stabil fuel conditioner . any help appreciated . ( low speed circuit stop up maybe ?)
     
  2. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    It does sound like it could be in the idle curcuit. If you can't get out of idle to midrange, you can't get to high speed.

    Do your new plugs both have spark?
     

  3. gearhead

    gearhead New Member

    Messages:
    274
    State:
    China Grove, NC
    It seems to run fine at at low ,mid, and high but you have to creep the throttle up and once your slightly moving you can go to full throttle .:crazy: If I just gun it , it will bog and cut off.
     
  4. CaTmAnDo55

    CaTmAnDo55 New Member

    Messages:
    154
    State:
    florence, SC
    it sounds like you have a tarnished carb. (gummed up) sounds like when you full throttle it your not getting enough gas you need to have them cleaned out. do you winterize your boat or run it year round. if you do winterize it do you run all the gas out the carbs?i would definitly have them cleaned before you go back out
     
  5. gearhead

    gearhead New Member

    Messages:
    274
    State:
    China Grove, NC
    IT just started doing this i fish all year long it never sits more than two weeks if that . i use a fuel conditioner with every tank full. the fuel cup screen is a very fine mesh and it was clean .I was hoping i would'nt have to go into the carb.I've cleaned lots of carbs im a ex motorcycle mech. but the throttle linkage system on this engine is what scares me.
     
  6. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    It's not all that bad to get to the carb. Just a few things related to the primer to get out of the way.

    The carb does have the fuel pump and primer attached as one assembly and there's a timing advance linkage that runs from the primer pump knob assembly back to the timer base. It looks just like a long S/S wire.

    Have you done a good visual inspection to see that it's all in the right place and working correctly?
     
  7. gearhead

    gearhead New Member

    Messages:
    274
    State:
    China Grove, NC
    I think i looked it over pretty good ,when my cables froze up one morning and all it would do was idle and I pushed on the throttle pretty hard to get some speed out of it as the day warmed up it freed up. it just could be gummed up but I was thinking that maybe I bent or streched something it started running a little funny the next time out.
     
  8. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    The best thing you can do is start taking it apart at the carb and look as you go for some malfunction, if you feel comfortable doing that.

    Before taking it apart, look closely at the primer operation and be sure the lever that pumps the little blue rod in the primer pump, is coming up completely.