1980 20hp mercury

Discussion in 'Bubba's Outboards' started by bigfish, Feb 18, 2006.

  1. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    the motor dosent have any reverse. had to take the cover nut out and the bearing carrier to replace the seals. was taking water into lower unit last year and didnt know it til saw lube leaking. probably had it out three times with the leak. did this water cause my problems inside with the gears. i was told to check and see if when flipping lever to change gears if the rod moves up and down. from what i can see this lever turns the shift rod not raise it. i gues i will take off the carb so i can see better how the linkage works i gues something on it could be loose, but it shifts the motor into forward and nuetral. i am afraid its in the lower unit. any advice would be appreciated.
     
  2. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    The mechanism wasn't in the right position when you reinstalled the lower unit, if in fact you removed it to change the seals

    Yes, it twists to change gears. Some move up and down
     

  3. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    hey bobpaul thanks for reply. no i did not have to remove the lower unit to change the seals. just the cover nut and baring carrier. but as i said i have only had this motor out 4 times, have never had a need to try reverse. should i take the lower unit off and try to re position it. how can i tell if it is positioned right.
     
  4. Cattracker16

    Cattracker16 New Member

    Messages:
    356
    State:
    Wilton Iowa
    boy ain't it fun working on the lower unit? i had a 35 hp evenrude i had the lower unit off prolly 12 -15 times i could never get the linkage just right, i finally gave up on the motor and bought a never style with all the bells and whistles.. not saying you should give up on it... was just my luck to find a great deal on a 40 hp 1990 w/tilt trim tack and h2o temp gage along w/ temp warning horn.. well good luck on the motor and shifter.. Kenny
     
  5. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    hey cattracker16 thanks posting. i could only hope it was only linkage problems. i just finnished taking off the carb and everything so i could see all the linkage and rod. everything down there looks fine. so im afraid the reverse gear might be worn out. the shop i called for advice said the reverse gear could be broke. i dont think this could be the case cause lower unit dosent make any noise like anything is rattling. my new problem is trying to get the lower unit off. there is supposed to be a nut on the bottom of a 4x4" plate that they call the trim plate. but it apears that the nut to take this off is down through a hole in the top of lower unit. which cant find a small enough socket to get down the hole. and a socket that would be small enough definately wouldnt be big enough to fit the nut. any one know how to get this trim plate off please help:crying:
     
  6. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Stand behind you boat and look straight down at the anticavation plate. Right where the point starts above the prop.
    There should be a plug in there. Take the plug out and it should expose a nut or the end of a stud.
    I think I am right on this my old brain ain't what it use to be .
    All my books are down in the shop and it is cold out so I am trying to recall from memory.
     
  7. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    hey bubbakat yes you are correct mine was missing the rubber plug. but that is what i was asking. i have every socket known to man, but none of them are small enough diameter to go in the hole. when i feel down in there with a screw driver i can feel the bolt and the threads and it feels like about a 1/4 inch bolt to me. now i know they put the nut on that bolt some how.
     
  8. Cattracker16

    Cattracker16 New Member

    Messages:
    356
    State:
    Wilton Iowa
    how big is the hole? do you have a 1/4'' socket set out? when i had problems with the rude i had to get out the 1/4'' socket set to work on it. the shift rod had a brass collarwith 2 -1/4'' bolts through it was a pain in the hiney i had to have the rods that the brass collar held in place just right or it wouldn't go back togather right.. and the clutch dog was very worn, not a good scenerio i did spend some on a clutch dog, but the gears were gone too far. that motor was a good runner except the lower unit needed all the gears and bearings replaced.. when it was a 1977 and the parts were going to cost me more than the new motor cost me i gave it away to a friend.. well he used to be my friend.. i dunno if that will help you any but i tried... kenny
     
  9. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Kenny this set up is entiryly different from a rude or johnson.

    The nut should be a 9/16 I have a socket in my shop I use but for the life of me I can't remember the make of it.

    You might try a 1/4 drive 9/16 and see if it will work. But don't pressure it to hard it might snap on you. The extinson bar I am talking about.

    When I get in tomorrow I will see what I use to get at that thing for yea.
     
  10. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    well the hole i beleive the nut is behind is only about 3/8 in diamater even a 1/8 inch socket is bigger round than that. this realy has me stumped. the manual also says remove plastic plug from rear of the drive shaft housing, unbolt and remove trim tab. this realy has me stumped. but on a good note i do have reverse problem fixed. i guess when i replaced the seals, and put the bearing carrier back i didnt have the cover nut tight enough. letting the bearing and reverse gear to have just enough slack. so when i came up with thish thought i just took it back apart and tapped the bearing in a little and put it back together. so now it goes into reverse fine. but i still need this lower unit off to replace water pump. the motor is 1980 dont know when last time {if ever} the water pump was changed. but cant change it if i cant get to it. i sure do appreciate all you guys trying to help me figure this one out.
     
  11. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    If you can see in the hole with the aid of a flash light, be sure it's a hex head and not an allen type head. I've not worked on alot of mercs, even though I own a 25 hp and have been known to shoot a roostertail with a 9.8 on a 14' jon.
     

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  12. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    well bobpaul i truly am:eek: right now its 11:30 but i had to go see, problem solved. dont know why i didnt think of that. guess i was just having a brain fart. now one last ? do you think i hurt any thing by not tightening that cover nut down enough. wasnt making any noise or anything just wouldnt go into reverse. after i tapped the bearing in a little and put the bearing carrier {dont know why they call it that} it just tightens down against the bearing. anyway tightened the nut back down and it goes into reverse now. the only thing i noticed is when you put it in forward and turn the prop it only grabs in one direction. but in reverse it grabs in both directions. is this the way its supposed to be. thanks a bunch on the allen wrench idea.
     
  13. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Well i'll be damned, guessed right again.

    I doubt you've done any damage, The lack of strange noises is a good thing.

    The grabbing issue is due to the slip ramp type gearing on the clutch dog in forward but not in reverse. It illiminates a shear pin.
     
  14. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    ps sorry i forgot just so happy to get most of my problem solved. but nice picture. :cool:
     
  15. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    well i guess i posted my last post same time as you did bobpaul, so after seeing yours, i have all my problems solved. well for one minute anyway. new to boating, and it seems like there is alot to learn.
     
  16. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Well I be dad gum I would never have thought about the allen head bolt.

    Awh the results of getting old I would say.
    Glad you got her fixed.
    Robert nice rooster tail you throwing there man.:)
     
  17. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Bubba, I clocked that ride at 21.5 mph with that 9.8 on that skinny little jon.

    It's nothing I'd recommend doing on a regular basis without a crash helmet.
     
  18. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    bobpaul you are exactly right. when i took my 16' out and loaded it down to see if i would have a weight issue, ducain rode on the front deck on the way to our fishin hole. i thought it was a little slow, but not to bad cause i enjoy the 25min boat ride any way. well on the way back the waves were kicken and ducain was gettin soaked. so i told him to come back where i was. when i throud that throttle it shocked me. dont know how fast but it seemed like 30 to 35 mph. not sure if my little 20 can move a 16'er that fast, but it sure seemed like it. anyway how can you see how fast your going.
     
  19. bigfish

    bigfish New Member

    Messages:
    432
    State:
    Dunbar WV.
    well i guess i will dig in yalls brains again. as i said i changed my lower unit seals to stop leak. well ran the motor that one time, and went ahead and drained lube. it was milky white. did i just sill have some water in there or is there some other seals or gaskets i should check.
     
  20. Bubbakat

    Bubbakat New Member

    Messages:
    4,532
    State:
    McMinnvill
    Did you chang the little round flat gaskets behind the fill and drain screws.

    I would refill and try again because Its hard to get all that water out the first try.