top bearing replacement question

Discussion in 'Outboard Maintenance' started by cslascro, Mar 9, 2013.

  1. cslascro

    cslascro I Love!

    Hello all,

    A source of great info in the past, I'm posing my questions about a top bearing replacement on a 2005 30hp 2-stroke Johnson here for all you gurus and shade tree veterans.

    I've got a high-rpm rattle/grind coming from the powerhead, and I've settled on a diagnosis of bad top bearing. I'm not 100% sure as I've never encountered this issue before, so I'm thinking of taking it to a shop to have it diagnosed.

    For anyone who's ever dealt with this, particularly on a small 2-stroke, what kind of cost am I looking at to get this fixed at a shop? What kind of labor time is reasonable to expect? If I plan to go the professional route, will it be better just to start shopping for a cheapo replacement outboard?

    Also, should I go ahead with fixing it myself, consulting the appropriate maintenance manual, of course? I'm a relatively experienced tinkerer having had the lower unit apart on this motor, disassembling carbs, replacing electrical components and other regular maintenance. I know my way around a motor fairly well, but I've never messed with a crankshaft bearing.

    Thanks for the help!
  2. Brett

    Brett > PRO STAFF <

    Never attempted to pull just the top bearing.
    Internal knock or grind meant it was time to pull the block apart.
    Make sure it is an internal problem, and not just flywheel contact
    to stator components that's producing the noise you're hearing.

  3. Creek Runner

    Creek Runner Well-Known Member

    Engine will need to be complelty dissasbmled, no way to replace the top bearing on those engines with out splitting the crank case.

    Might as well at least hone and re-ring, and replace anything else thats needed.

    Just the bearing and labor $350+ (parts about $80+ and the rest is labor.)

    $800+ depending on parts needed for the honing and re-ring.
  4. cslascro

    cslascro I Love!

    Thanks CreekRunner.

    Flywheel contact to stator components...hmmmm.....

    Is this really a likely possibility? If so, will replacing the stator eliminate it?
  5. Brett

    Brett > PRO STAFF <

    Electrical components are mounted to the stator plate with machine screws and lock washers.
    Vibrations will loosen the screws and allow the components to shift position thereby making contact
    with the underside of the flywheel. If you have to pull the block anyhow, you're going to have to pop
    the flywheel. Pull it and check the electrical components for position shift. Also scuff marks
    of bright metal where the rubbing/contact occurs.  I've had it happen a couple times over the years.

    The components that can move are 30, 35, 45 in the linked diagram
  6. cslascro

    cslascro I Love!

    Nice. Thanks, Brett! That helps a ton. I'll go ahead and pull the flywheel just to take a look. If that's not it, I'll just have to go from there.