Unusual amout of oil in the test tank

Discussion in 'Outboard Maintenance' started by bribar98, Mar 11, 2011.

  1. bribar98

    bribar98 I Love microskiff.com!

    I dropped my 1975 Johnson 25, 2 stroke into the test tank after replacing the plugs and spraying de-carb in the carb.  When I fired it up, it ran like a top.  After the test I noticed an unusual amout of oil in the test tank.  Could I be leaking lower unit oil somehow?  I mixed my oil/fuel a little lean according to directions @ about 30%.  How many seals are there in the lower unit that I would have to replace?
  2. Brett

    Brett > PRO STAFF <

    Welcome to the realization that 2 strokes are extremely inefficient engines.


    At idle speeds a 2 stroke wastes up to 40% of the fuel oil mix.
    It's dumped straight out the exhaust. That's what you're seeing.
    Engine efficency improves as rpm's are increased.
    At top speeds only about 8% of the mix is wasted.
    That's the reason that the EPA established new emission requirements.
    Most manufacturers have switched to 4 stroke tech in order to meet the regs.

  3. topnative2

    topnative2 Well-Known Member

    fire her up and put it in gear for 2min and then ck the lower unit oil if it is milky u got h20==---otherwise I am w/ B.