90 hp merc

Discussion in 'Bubba's Outboards' started by whitney weese, Jun 18, 2008.

  1. whitney weese

    whitney weese New Member

    Messages:
    104
    State:
    oklahoma
    Having a problem with my moter. the boat runs fine when just idling but when im about to plane out. thats when the problem starts. its like i loss my prop. i was told that there is two gears in the lower unit that have dog ears on them. that switch from low to high. and if it is rounded just a little. than it will kick it out to low. is this the case and how much does this part cost. i was told that i would have to replace the whole dog leg. would like to get it fixed soon and get back to fishing. Or is it something elses
     
  2. oh no

    oh no New Member

    Messages:
    11,108
    State:
    Indiana
    Is the hub on your prop slipping. Or do you have a key sheared.

    I have a 99 90 HP Merc and I know nothing of a 2 speed deal. Its motor to the gears that change the direction and then there is the prop. I would look at that prop real close. Pull it off and see if a key is sheared, or if it wants to slip on that rubber safety sleeve thats in the prop.

    The only other thing would be the wrong pitch prop. If you have added a lot of extra weight or changed the pitch, sometimes it will just spin and spit air. Thats because it's trying to move too much water before the boat starts moving. You need a lower pitch prop then. Kinda like the gears in a car.
     

  3. whitney weese

    whitney weese New Member

    Messages:
    104
    State:
    oklahoma
    the pin is good and its the same prop that i have been useing for over a year.
     
  4. whitney weese

    whitney weese New Member

    Messages:
    104
    State:
    oklahoma
    well the pin looks good. its bras and has 4 ribs that are not rounded off
     
  5. oh no

    oh no New Member

    Messages:
    11,108
    State:
    Indiana
    Where's Bubbacat and the professionals on this subject.
     
  6. whitney weese

    whitney weese New Member

    Messages:
    104
    State:
    oklahoma
    dont know. i hope its a resonable fix. and not cost an arm and a leg
     
  7. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    There are 3 gears in your lower unit, Forward, reverse, and the drive gear attached to the drive shaft. Those 3 gears are in constant motion, Forward and reverse are on the prop shaft. Between those two gears is a clutch dog, that engages one or the other, depending on which way you want to shift.

    Your clutch dog is splined and pinned to the prop shaft, and is slid forward or reverse, to make contact with either gear. It is motionless in the nuetral position.

    Your loss of gear contact is usually a worn clutch dog, that kicks out under pressure.

    A worn clutch dog, is attributed to slow shifting, and just plain using your motor for a long time. When the clutch dog is worn, so are the contact lugs on the forward and reverse gears.

    Sometimes, just replacing the clutch dog is enough, but not always.

    When a clutch dog kicks out, you usually hear and feel a bang, of sorts, when it lets go of whatever gear your connected to.

    Another possibility is a spun prop hub, or in some cases, a shear pin. Look at that FIRST.
     
  8. whitney weese

    whitney weese New Member

    Messages:
    104
    State:
    oklahoma
    the sher pin looks good. not even a dent in it and the boat runs at low speed. if it was the sher pin it wouldnt move. on replacing the clutch dog. is that an easy repair or should it go to a shop to be replaced.
     
  9. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Take it to a shop.
     
  10. Winkstr

    Winkstr New Member

    Messages:
    46
    State:
    Missouri
    I have an older 115 hp merc and we spun the hub on the prop. It acted about the same. What we did to check this was to paint a small portion of the inside of the hub and the metal part of the hub, let it dry and then went out and ran it. if the hub is slipping you will see the paint lines do not line up. I Believe the cost to repair this was around $50 to $65. I hope this helps.
     
  11. whitney weese

    whitney weese New Member

    Messages:
    104
    State:
    oklahoma
    i will give this a try. but looking at the pin. it look fine. the edges are still square. not rounded off or even bent or dinged
     
  12. Big Vic

    Big Vic New Member

    Messages:
    664
    State:
    Nebraska
    I have had the prop on mine spin the hub also. And it acted just as you say soon as you want to put the power to it it let go. This has nothing to do with the shear pin !! it is the rubber part between the center of the hub and the outside where the prop blades are.
     
  13. whitney weese

    whitney weese New Member

    Messages:
    104
    State:
    oklahoma
    is that any easy fix or do i need to buy a new prop
     
  14. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    If the prop is in fact slipping on the hub any prop repair shop can fix it.