johnson 50hp help

Discussion in 'Boating and Boat Rigging' started by boomer_x7, Jul 3, 2012.

  1. boomer_x7

    boomer_x7

    Messages:
    3,220
    Likes Received:
    309
    Location:
    location location
    I have been helping a friend work on his 1974 johson 50hp outboard. he had the carbs rebuilt because it wouldnt run but after he got it home it ran once or twice at very low power and then wouldnt run. I checked lines, tank, changed the primeing bulb and rebuilt his fuel pump and had some results with that. We could get it to run for 10 seconds. After we had it "running" i started to adjust the carb and it just died out. After that it would fire 7-8 times full choke and then die. I took the intake cover off and noticed brown oil in the intake. Could also see where the airflow was sucking it into the carb. I do not know much about outboards and was hoping some one could tell me what it is from. It apeared to be coming from a small hole in the bottom of the intake housing. Its the small hole on the bottom corner of part number 28 http://www.marineengine.com/parts/j...&manufacturer=Johnson&section=Intake+Manifold

    This was also the first time he had the motor tilted when i got to his house witch im guessing was the cause.

    Also would it possable for the oil to block the carb and keep fuelfrom flowing through it causeing lackof fuel. I wouldnt think oil in the fuel would cause it toonly fire with full choke.
     
  2. CHASINEYES

    CHASINEYES

    Messages:
    14,493
    Likes Received:
    13,411
    Location:
    lapeer, county
    Is this oil the same color of his premix oil? 2 strokes will develope puddles of oil throughout the intake tract and also the crankcase. This oil started out as a thin film left behind from fuel passing through. Fuel evaporates, oil left behind runs down forming puddles.

    If your engine fires only while choked, your lacking fuel.

    Outdoor Hub mobile, the outdoor information engine
     

  3. Naden fourteen

    Naden fourteen

    Messages:
    204
    Likes Received:
    0
    Location:
    Mt. Morris
    If there's fuel in the float bowl, I'd take a real close look at the fuel passages to and from the needle valves. use compressed air to clear any crud that might have flaked off and clogged 'em up. You see it a lot in outboards that don't get the fuel hose disconnected dockside at day's end and allowed to run out of fuel. I had a 50-year old Johnson that NEVER needed carb work, because my dad and later, I ALWAYS ran it dry before the boat left the water...
     
  4. boomer_x7

    boomer_x7

    Messages:
    3,220
    Likes Received:
    309
    Location:
    location location
    The oil is brown. Looks like new motor oil.. Deff.not 2-stroke oil!

    The next move is to open the carbs and see whats inside.... They where saposedly rebuilt about 5 weeks ago so that was the last thing i was going to do. And he is one of those guys that never drain replace a thing....