Where there's smoke?

Discussion in 'Outboard Maintenance' started by redgheenoe, Jun 7, 2009.

  1. redgheenoe

    redgheenoe Well-Known Member

    200
    0
    391
    I bought a used classic about 3-4 weeks ago and when the seller demo'd the motor in a tank it started fine and had a good water stream.  It did smoke quite a bit at first and he said his mix was a bit rich.  I have had a 4 stroke for a while now and always heard you guys call them 2 smokes so I didn't think anything of it.  I finally had a chance to start the motor this weekend in a tank and it smoked from the lower unit and I noticed no water stream.  I shut it down right away.  Residual smoke kept coming out of the lower unit and a bit of black residue from the prop.  I drained the lower unit oil to replace it and it was a good color.  I am assuming I need a new water pump.  Can anyone tell me what else I might check and if the smoke from the lower unit can be a sign of something major?

    Thanks
     
  2. Taterides

    Taterides Well-Known Member

    541
    0
    391
    Sometimes it takes a few seconds for the water pressure to build. I would let it run 20 seconds or so before I got too worried. One major exhaust point is from the prop/lower unit area, smoke from that area and some residue is normal for 2 smokes. 
     

  3. Un-shore

    Un-shore Well-Known Member

    You have to submerge the lower unit enough for the water level to reach the water pump otherwise it won't pick up the water.

    Smoke is okay from the lower unit if it is coming from the exhaust port that could be under the cavitation plate or the propeller hub depending on the motor.
     
  4. redgheenoe

    redgheenoe Well-Known Member

    200
    0
    391
    Thanks for the replies. I am going to try again tomorrow and let it run longer and see if it will pee.
     
  5. Taterides

    Taterides Well-Known Member

    541
    0
    391
    Sounds like we are training a dog...... ;D
     
  6. goodhands_gheenoer

    goodhands_gheenoer Well-Known Member

    159
    0
    341
     
  7. B.Lee

    B.Lee Well-Known Member

    The black oil from the exhaust can be a couple things.

    Too rich on the oil/fuel mixture, or cheap oil. Lubrimatic and other cheap oils do smoke a lot more and don't burn as thoroughly as better oils or synthetics. The cheaper oils still work, just dirtier inside your engine.
     
  8. goodhands_gheenoer

    goodhands_gheenoer Well-Known Member

    159
    0
    341
    I changed the lower unit oil this morning with Pennzoil marine. I have Quicksilver Premium Plus 2 cycle oil for the gas. Do you mix yours 50:1