Mercury 2 stroke 150 outboard dies at full throttle

Discussion in 'Outboards' started by Bobs201, Jul 23, 2018.

  1. Bobs201
    Joined: Jul 2018
    Posts: 3
    Likes: 0, Points: 1
    Location: SC

    Bobs201 New Member

    My 2003 2 stroke 150 merc runs fine at 1/2 throttle but dies out at full throttle after about 3 mins. It begins to sputter until I either ease off the throttle or it shits off. It it hard to start after shutting off and cranks similar to trying to crank it with the kill switch off. I have changed the fuel filters, had carbs needes replaced, new spark plugs. My mechanic thinks its a CDM, or Stator. Any suggestions on how to locate the problem?
     
  2. ondarvr
    Joined: Dec 2005
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    Location: Monroe WA

    ondarvr Senior Member

    Try pumping the squeeze bulb right before it dies, if it stays running it's a fuel delivery issue.

    After it dies immediately check for spark.
     
  3. BlueBell
    Joined: May 2017
    Posts: 720
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    Location: Victoria BC Canada

    BlueBell Ahhhhh...

    Most likely a fuel delivery issue. Fuel pump?
    Second most likely, electrical; no spark.
    A mechanic may be able to swop some parts out as a diagnostic process.
    Has any work been done recently on the engine?
     
  4. Bobs201
    Joined: Jul 2018
    Posts: 3
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    Location: SC

    Bobs201 New Member

    Yes, in attempt to correct the problem, spark plugs, and carb kit
     
  5. Bobs201
    Joined: Jul 2018
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    Location: SC

    Bobs201 New Member

    Will a fuel pump or CDM/coil pack fail intermittently?
     
  6. BlueBell
    Joined: May 2017
    Posts: 720
    Likes: 71, Points: 28
    Location: Victoria BC Canada

    BlueBell Ahhhhh...

    It's not an intermittent symptom if it's failing predictably after ~3 minutes at WOT and it runs fine at idle and 1/2 throttle, no?
    Preempted by sputtering (fuel starvation symptom).
    It wreaks of a fuel delivery issue.
    Fuel pump not being able to keep up or a dirty fuel channel in the carburetor perhaps.

    No work done previous to these current symptoms?
     
  7. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    You need a good mechanic to troubleshoot the problem. If he is changing parts to see if he gets lucky, go somewhere else. It may be one or a combination of problems.
     

  8. Mr Efficiency
    Joined: Oct 2010
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    Location: Australia

    Mr Efficiency Senior Member

    Certainly sounds like fuel delivery issue, maybe blocked filters restricting the flow rate, ondarvr's suggestion ( have someone squeezing the bulb as you run along) would confirm a fuel issue, if it keeps running. You could have a fuel line that is sucking air at a connection somewhere along it, and if you have a spare primer bulb, switch, they can cause problems with age.
     
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