Merc 25 acting like a Merc

Discussion in 'Outboard Maintenance' started by brew1891, Aug 1, 2009.

  1. brew1891

    brew1891 Well-Known Member

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    Ok so my 2001 Merc 25 2-stroke that has been flawless is now acting up.

    It ran great today on the water. As soon as I got home it will not run at all. Awesome that it runs great and won't run 45 mins later. Maybe it is mad I didn't offer it any of the Louis' BBQ I was pigging out on after fishing.

    It has electric and pull start. Neither work. The starter is spinning the fly wheel but absolutely nothing is happening. Not even a sputter. I can hear the primer injecting fuel, the fuel bulb is firm, and the interior filter is full of gas which appears as it should.

    It really almost seems like the kill switch is in the off position but trust me it is set to "run". I have checked at least a dozen times.

    Anyway to bypass the kill switch to see if that is the problem?

    It's almost like something wiggled free on the way home but everything looks to be in place.
     
  2. Brett

    Brett > PRO STAFF <

    Follow the wires from the kill switch back,
    one goes to ground (the engine block)
    the other to an ignition circuit.
    Whichever is easiest to disconnect, do so.
    Kill switches do go bad, and replacement switches are an easy install.
     

  3. Shinerkiller

    Shinerkiller Well-Known Member

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    It should be the (Power Pak)Switchbox. part # 855713A 4
     
  4. brew1891

    brew1891 Well-Known Member

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    The switchbox appears to be sending power to the coils.
     
  5. B.Lee

    B.Lee Well-Known Member

    Do you have any spark then? Pull both plugs, put them back in the plug wires, ground the threads on the engine somewhere, and see if they are sparking while cranking.

    I'm always suspicious of a really good-running 2-stroke, it's normally a sign something is going wrong!
     
  6. Brett

    Brett > PRO STAFF <


    Optimist... ;D
     
  7. brew1891

    brew1891 Well-Known Member

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    Yes, spark in BOTH plugs

    I disassembled the kill switch on the lower cowl. It is a simple switch. two wires, switch slides a metal contact up and down to complete or break the circuit. nothing looked messed up.

    Haven't looked at the switch on the end of the tiller arm
     
  8. Brett

    Brett > PRO STAFF <

    Just to state the obvious
    if you have spark at the plugs
    then the kill switch is not activated
    look elsewhere for your problem

    Spark has been checked.

    Fuel
    air
    timing
    compression
     
  9. rkmurphy

    rkmurphy Well-Known Member

    I'm going to go with carb. Pull it and clean it. Can't hurt.
     
  10. mark_gardner

    mark_gardner I Love microskiff.com!

    thats would i would do, i had problems with mine a few weeks ago so i pulled it, cleaned it, and all's well atleast for now :) definitely sounds like a fuel problem though, if all else fails tow it back to the bbq place and give her what she wants :D it cant hurt to try and you'll be able to take care of the appetite you worked up trying to fix it ;)
     
  11. topnative2

    topnative2 Well-Known Member

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    are the plugs wet after u try to start

    if they are dump the carb bowl try again>no luck >pump some gas into a glass jar and ck h20 content

    if u got water get a fresh mix and wrk out the ole gas in the line and carb

    what happens is the gas and water in ur tank get mixed up during the day and the problem starts latter


    change ur gas
     
  12. brew1891

    brew1891 Well-Known Member

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    No water in the gas. Pulled the internal filter (I also have a remote mounted fuel/water seperator) and it looks great. There is just no easy way to drain the carb bowl is there?

    [​IMG]

    Bulb pumps gas well.

    Here is one of the plugs...not wet but not pretty:

    [​IMG]

    [​IMG]
     
  13. Brett

    Brett > PRO STAFF <

    http://www.crowleymarine.com/mercury_parts/3236/110.cfm

    I don't see a carb bowl drain in the diagram
     
  14. noeettica

    noeettica Well-Known Member

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    I just pulled the carb on mine ... Two 8mm bolts on Plastic enricher/spark advence Then two Nuts behind carb ... Gotta wiggle everything just so ... Pull fuel line then Vacum line ... 1 Bolt and bowl is off ... Mine was Like New Inside LOL

    These Motors Do not Idle well at all ... !

    Can ya pull plugs and look for spark ?

    Did Not read enough of the thread LOL ...

    Give it a shot of starting Fluid .... If it fires then it is carb ...
     
  15. topnative2

    topnative2 Well-Known Member

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    ok---get some quick start spray it in the carb and see if it will fire off >do not try to keep it running< if it does not fire off >and the carb has been ck or redone the problem is under the fly wheel like timing etc. :(
    shop time

    I would start over w/ cking fuel feed, spark, and new plugs etc. to make sure u did not miss something u got spark that means power pack and coils are good 99% of the time--see if it fires up on the quick start that will tell u alot
    good luck--let us know

    da! ditto above
     
  16. brew1891

    brew1891 Well-Known Member

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    found a way to drain the carb without pulling it.

    turned it over a few times and then hooked fuel line back up and started the starting process over. still not working.

    time to call the shop.
     
  17. topnative2

    topnative2 Well-Known Member

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    quick start first it will not hurt it---if it starts definetly the carb--u can do a rbuild yourself
     
  18. brew1891

    brew1891 Well-Known Member

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    forgot to mention that I opened the butterfly and looked inside the carb with a flashlight. Saw some gunk in there.
     
  19. topnative2

    topnative2 Well-Known Member

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    ok [smiley=1-beer.gif]
     
  20. Gramps

    Gramps Living &amp; Dying in 3/4 Time

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    Those carbs are easy to rebuild, get a gasket kit for about $30 and get at it. Rebuilt mine when I first bought the motor and it is the dogs bollocks. These motors are smooooth when tuned correctly, from idle at 700rpm to wot 6000rpm no lag, miss or bog.