2005 Mercury 4stroke 40

Discussion in 'Outboard Maintenance' started by bodenhamerb, May 18, 2010.

  1. bodenhamerb

    bodenhamerb Well-Known Member

    Hi, im new to microskiff ive always turned to it for reviews and tips but just decided to actually join. (this is my first post on here) I have a 40hp mercury 4stroke that runs full out but then decides to bog down and studer, it doesnt shut off but it wont get back on plane. the weird part is that if i restart the engine it runs great then bogs down again, over and over again. ive changed the coils, plugs, filters, gas line, fuses, checked the injectors, air intake, and vst tank but nothing will stop it from bogging down. Does anyone know why it is doing this. some people told me it could be the tank but before i go buy a $300 tank i wanna know if it is that. Thanks
  2. DuckNut

    DuckNut Brandon, FL

    There is a place in Pompano on the west side of Dixie directly across from the blimp (outboard shop - I believe). Could possibly arrange for a test drive with one of them. It is a Mercury shop.

  3. Brett

    Brett > PRO STAFF <

    Borrow a small tank and hose assembly.
    Fill it with fresh gas, hook it up and go for a test ride.
    If the engine runs properly, then you know the problem
    is not under the cowling.
  4. mark_gardner

    mark_gardner I Love microskiff.com!

    dang it!! once again brett beats me to the punch :D ;D do as he says then report back ;) :cool:
  5. bodenhamerb

    bodenhamerb Well-Known Member

    Yea, i was planning on trying that this weekend when i get the chance. I want to really get it working for this great night tarpon bite that is going on now
  6. bodenhamerb

    bodenhamerb Well-Known Member

    i Bought a new 6 gal portable tank and hooked it up friday night. WoOOW what a difference. i can run full out no problems and actually it increase in my speed. but i still need to clear my in engine inline fuel filter cause there is still junk in the line
  7. Brett

    Brett > PRO STAFF <

    Now that you've figured out the engine is not the problem,
    Replace the fuel line assembly from the engine to the fuel tank.
    Replace the filter in the fuel/water separator.
    Drain the fuel tank, inspect the gas for contamination.
    Remove the pickup tube from the tank, clean it, reinstall.
    Remove the inspection plate from the tank, verify no sludge left in the tank.
    Reassemble everything, refill tank, test ride again.

    Bring the spare tank with you... ;)
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