Am I running on one cylinder?

Discussion in 'Outboard Maintenance' started by jgregory01, Oct 18, 2010.

  1. jgregory01

    jgregory01 I Love!

    I have a 1999 Johnson 50hp 2stroke on a 16 foot c/c. Was on the lagoon sunday and she ran great for the first hour. Started making a run with the engine wot. The engine started making a noise, as if grass were on the prop and I lost power. Powered down, trim up and no grass. WOT again then a few moments later same thing, power loss and a strange noise from the motor.

    One more of these and she gave out. Would not start again. My partner thought it was getting starved for fuel. 3/4 of a tank. bypassed the fuel/water seperator and still would not start. trimmed up to look at the plugs and the lower plug had a significant amount of corrosion on it. Around the metal part the socket holds onto. Pulled the boot and it looked ok but still would not start.

    My friend, who is more mechanically inclined than I am, thinks it wasnt getting a good spark because of the corrosion. I have not had a chance yet to test the theory.

    Any other ideas? no alarms from the motor and regularly maintained by a good marine mechanic. When trying to restart it would start to go...made some gruting but would just die out.
  2. Brett

    Brett > PRO STAFF <

    Replace the sparkplugs
    Disconnect old fuel line and tank
    Drain fuel system on outboard
    Obtain another tank and fuel line
    Fill with fresh 2 stroke mix
    Hook up the new fuel line and tank
    Prime the system, see if she'll run...

  3. jgregory01

    jgregory01 I Love!

    Just an update. It was the flywheel. Some magnets fell off and that was the cause of the problem. I was able to locate a used flywheen for just over they are 350 or so. the magnet replacement kits work? Im curious if gluing a magnet onto an object that is spinning so fast is wise.
  4. Frank_Sebastian

    Frank_Sebastian Well-Known Member

    I won't go into how "wise" it was to glue the magnets into the flywheel, but checking them frequently and re-gluing them became an important part of engine care. I don't know why you had to buy a new flywheel, but I have re-glued the magnets in a lot of OMC engines. You can buy the kits from an OMC dealer or you can use a "wet patching epoxy" product. That is what OMC sells you as part of the kit.

    On my 225 Evinrude I used high temp epoxy from Raka. That engine is now almost 20 years old and still in service.

    The magnets should be checked every year or so. With the engine cold and the key removed you reach up under the flywheel edge and try to move the magnets. If any of them move, then pull the flywheel and re-glue.

    Best regards,