2004 Yamaha 50HP 4 stroke

Discussion in 'Bubba's Outboards' started by vlparrish, Mar 28, 2009.

  1. vlparrish

    vlparrish New Member

    Messages:
    1,276
    State:
    Bedford, Kentucky
    My buddy Ross has a four stroke Yamaha. it runs out fair and gets up on pad good, but when you first throttle into it, it will chug out at times. I was wondering about rich/lean adjustments on these motors, it has four carbs and a small silver screw on the side of each that looks like a set screw is this the carb adjustment screw? Vern
     
  2. metalman

    metalman Well-Known Member

    Messages:
    3,457
    State:
    IN
    Name:
    Winston
    Vern,
    The rich/lean adjustments won't have changed themselves so if the motor is in need of adjustment then something has made that change necessary. If you can find that reason then adjustment may not be needed.
    No doubt that carb cleanings/rebuilds are beneficial but there are a couple of things to try before that.
    If the float bowls on the carbs have a drain screw, back them out and drain the bowls. Have a clean white rag ready to catch what comes out of the float bowls. If there is a lot of sediment then a cleaning is in order.
    If there isn't a lot of dirt then the carbs may have some gum in them. Have him run a few tanks of Sea Foam through it and see if that improves things.
    A new engine fuel filter never hurts and a Racor water separating fuel filter between tank and motor will prevent anything getting to the motor and is a great investment.
    ...W
     

  3. PeeDee Cat

    PeeDee Cat Member

    Messages:
    351
    State:
    SC
    I have a 40 4 stroke yama had the same problem put a factory in line fuel water separator and some fresh gas and had no more problem.
    PEEDEE CAT