1974 evinrude 50hp

Discussion in 'Bubba's Outboards' started by basebklyn7, Jun 25, 2006.

  1. basebklyn7

    basebklyn7 New Member

    Messages:
    50
    State:
    dubuque, iowa
    i have a 1974 evinrude 50 hp that i recently acquired. got her on the boat and started her up in the driveway in a tank of water with a hose running in it.
    she idled excellent for the 5 minutes she was running before i decided to shut her down. the reason for this is... there was no water coming from the tell tale.. on my 33 hp it would shoot water from the telltale the second you fired it up and until you shut it down. i was reading on a site that this motor has "auto pressure temp control, warning buzzer" so does it wait until it gets to a certain temp before it starts pushing water?? or???
    i already have plans to get a new impellar/water pump ASAP as i know it wont hurt having a new one. i dont want to run it if its not going to cool properly.

    btw.. the model number is 50473M.. thanks again for any input..

    it has a different cowl on it.. i have the original but the seal on it is bad.

    [​IMG]
     
  2. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Look for the tell tale hose and see if you can find it.
     

  3. basebklyn7

    basebklyn7 New Member

    Messages:
    50
    State:
    dubuque, iowa
    after work tomorrow i will take a closer look.. are you thinking that the telltale hose is disconnected or clogged??? will this require me to take the motor apart to look for it??? thanks

    sean
     
  4. catseeman

    catseeman New Member

    Messages:
    1,189
    State:
    Indianapolis, Indiana
    Some engines have thernosats. So until it reaches operating temp. no water comes out . MY 67 /40p bigtwin scared me at first. Check with parts supplier for one.
     
  5. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    I'm saying that I don't see a port in the lower cowling for the discharge, and it may not have one. It might be just like the older ones with a discharge after the thermostat opens.

    I always put in a new water pump with any engine I get. A new thermostat should also be installed when you do a water pump. They work together for proper engine operating temp.
     
  6. basebklyn7

    basebklyn7 New Member

    Messages:
    50
    State:
    dubuque, iowa
    [​IMG]

    [​IMG]

    [​IMG]

    heres a couple photos i took this evening.. maybe give you a better idea..

    you would think water would come out of the 2 holes on the rear of the motor... after starting it in the driveway.. air blows from these holes (exhaust?) for a couple minutes.. then stops. ?

    sean
     
  7. basebklyn7

    basebklyn7 New Member

    Messages:
    50
    State:
    dubuque, iowa
    i got a few more pictures for ya's of the actual motor idleing. i let it run until the head of the motor was getting close to too warm to touch. then shut it off. the first picture is of the motor running of course.. and the second picture is the motor right after turning the water off, engine off too.

    [​IMG]

    [​IMG]

    i called a local marine place today and said they could get me a water pump kit for 73.99 and a thermostat and gasket for it for like $24. thats a lot more than a water pump kit for my 33 ($22). anyways.. im probably going to switch both out and was wondering if this model of motor will be similar to taking apart like my 33. it has electric shift whereas the 33 had manual shift.. what other problems will i come across doing this myself??? thanks again.

    sean
     
  8. Trapper-steve

    Trapper-steve Well-Known Member

    Messages:
    1,101
    State:
    Bicknell, IN
    All I can suggest is buy a repair manual while you're in the buying mood:smile2: GOOD LUCK
     
  9. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Yup, you need a water pump, thermostat would be real nice too.

    They won't be difficult to change. I think the shift shaft disconnects underneath the carbs. Wait!!! It's electric shift. no shaft, but I'm sure there's a wire that needs disconnected

    There will be a wire to the lower unit that needs disconnected. I have no idea where. Never worked on one, nor even seen a diagram.

    You'll need the proper lower unit oil, and I'm told it's been out of production for a long time. Got no idea what you can use. I know some older shops have some hidden away. You've got to hunt it up.

    Bubba , can you help him on the wire disconnect or the oil?
     
  10. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
  11. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Wires to the lower unit are blue and green. Interesting wires. LOL. They are located on the starboard (right) side of the engine, and have a disconnect on them.

    A man that works on these old motors told us (my friend FuzzFace and I) that you are to use a type c lower unit oil. However, he said if you could find it, it was quite expensive ($5.00 qt, minimum) and we should use dextron transmission fluid instead.
     
  12. (GutMaster)

    (GutMaster) New Member

    Messages:
    10
    State:
    VIRGINIA
    I have the same problem with mt merc (50)hp it's in the early 70's. No water shoots out the pee hole but the motor does not get hot...Any clue?
     
  13. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Blow compressed air into the pee hole and knock out what's in the line. If it doesn't pump out then, take the discharge line off and find out why.
     
  14. basebklyn7

    basebklyn7 New Member

    Messages:
    50
    State:
    dubuque, iowa
    made a call today to a local boat parts store for parts for my motor....i got into explaining to him what my problem was and he told me that this particular style of motor, while in idle will not "spray" water. he then said if you let it idle for 10 minutes and it was still cool enough to touch (which it was) then it is probably cooling properly.. ?

    im getting 2 different answers to my problem... i know im still going to replace the pump and thermostat in time.. (fixing my other motor now and money is kind of an issue, at $100 for part especially) i was hoping to get the boat out over this upcoming 4th of july weekend.

    im in a predicament.. what should i do?????
     
  15. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    Gotta scratch my head on this one also. Took pictures with the motor running. Have no idea why I'm not getting any water from the exhaust, unless the pumps out. Have to wait until I get the shop manual in to find out, I guess. The first picture shows water exiting from the two holes on the starboard (right) side of the engine before it is started. The second photo shows an area that water comes out of when the motor is running. The upper stream of water is gone when the motor runs. I'm stumped...guess I should have been born rich so I could just buy a new engine.
     

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  16. basebklyn7

    basebklyn7 New Member

    Messages:
    50
    State:
    dubuque, iowa
    thanks for the reply... when my motor idles.. it has water coming out of a few areas on the lower part of the unit (see pictures earlier in post) but only a very seldom, faint spit out of the two holes seen in picture below while idling.. im assuming this is the "telltale" as its the only place i can see water would come from if the motor would be submerged in water. ? im stumped.. i keep getting different answers to the problem.. grrrr...
    [​IMG]

    sean
     
  17. basebklyn7

    basebklyn7 New Member

    Messages:
    50
    State:
    dubuque, iowa
    dextron transmission fluid? just want a confirmation on this.. also.. whats the reasoning that i can't use normal gear oil for the lower unit???? thanks.

    sean
     
  18. Bobpaul

    Bobpaul New Member

    Messages:
    3,039
    State:
    Supply NC
    Yes, transmission fluid.

    2nd question, because it won't work.:lol:
     
  19. basebklyn7

    basebklyn7 New Member

    Messages:
    50
    State:
    dubuque, iowa
    :big_smile: :big_smile: :big_smile: lol... i understand.. but... whats the reasoning?

    how is this lower unit different (besides size) than my 33 evinrude??
     
  20. AwShucks

    AwShucks New Member

    Messages:
    4,532
    State:
    Guthrie, Oklaho
    My understanding is that the regular fluid is so thick it will not lubricate the parts in the lower unit, causing failure and expensive repairs. Maybe the ports (holes) are small, don't know. I know you use 90W oil in a car/trucks rear axle, and only a few of those will take 90W in the transmission. Gotta go with what the engineers have said, and they said a type C fluid, not the regular flood.

    I thought those two slots were the exhaust for the water pump, and that the pee holes were the little small streams that comes out the sides of the motor. Never saw a water pump exhaust out of the side.