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Johnson 9.9-Power Loss

Discussion in 'Boats and Motors' started by WoodenShips, Jun 15, 2005.

  1. I have a 1998-Johnson 9.9.I have trouble with power loss.Motor starts out at 5600 to 5800 RPMs and 10 to 12 MPH.After about 1/2 hr to 1 hr running time the motor drops down to 5000 RPM and about 6 MPH.The plugs are new.The top sparkplug looks fine but the bottom is a little oily.

    What do you think the problem might be?
    I think it's a COIL going bad???????

    The scheduler at the mill asked me if I wanted to take a vacation next week.
    I said "HELL NO!........MY boat is going in the shop Friday and get worked on.
    "IF I can't go fishing it wouldn't be very good vacation." :DShe laughed then I said-HOW ABOUT THE WEEK AFTER! :) 27 years in the mill and it's hard to get a summer vacation and I turn one down.
  2. misfit

    misfit MOD SQUAD

    sounds like possible coil,plug or wire,breaking down,from the symptoms.i've had the same problem with coils before.

  3. smallieguy

    smallieguy Smallmouth Please

    it could be overheating too, I just had the same type of trouble
    with mine and it was the water pump.
  4. johnboy111711

    johnboy111711 SOLID MEAT

    make sure the gas cap is loose, i have had the lack of preasure build up as the gas is sucked out cause motor problems.
  5. Coil breakdown due to heat
  6. Thanks guys

    Don't think it's over heating because there is a real nice stream of water coming out. :) Just like if you drank 10 beers and had to WIZ!.lol

    Gas tank is built in and has a nice vent to the tank.
  7. I forgot to post a reply about the motor.It was the COIL.Motor is running fine but they did say the POWER PACK is losing a little power too.The guy said it shouldn't make that big of difference.