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  1. #1

    Fx140 NIGHTMARE!!!!

    I have been wrenching on this MR1 platform for quite a long time, Ive fixed many many many a skis over the years, BUT this one is about to drive me insane. There were a lot of things wrong and i have had to systematically go through and figure them out one by one, but not for lack of effort, im pretty much at the end of the road with this ski. EXCEPT for a motor tear down...


    It was a neglected 04 fx140 cruiser from the get go. Initially the owner thought it was seized up and was preparing for a new engine. But it was a combination of about 6 different things that caused it to have issues. First starting with a seized impeller housing....After i got that fixed the ski also had a few other problems with it. The TPS, cam position sensor, intake pressure sensor, fuel pump, thermostat, battery, stator, and I even pulled the motor and because the ring joint on the exhaust system went bad all have been replaced

    After spending a metric shit ton of time on the ski it runs.but with issues...in fact it runs well, when its not on the hose...

    The engine was NOT overfilled with oil this time around but was off the batt, new plugs after re installing the motor...

    When the ski not in the water and on the floating dock, she will run till she makes her first over heat warning, purring like a kitten i revving up and coming back to idle perfectly....when i dip the rear end of the ski in the water and leave the bow on the dock itll still run under slight load....but only when i put the ski fully in the water does it die..i used to die after about 10 seconds, after the ring joint install, itll last about 45-60 seconds and then eventually die..slowly...but if i blip the throttle, once it comes back down, itll die..and now it fouls the plugs sooty and black, where it used to water foul them..i have always 140-150 psi on all 4 cylinders, but that doesnt denote a good head gasket ever...but my next question is...do i have a blown head gasket?? or can someone think of anything im missing???


    I have a second perfectly working fx140 to take and use parts from to test....

    I have tested the entire fuel pump assembly(even after replacing pump) with a known working unit with no change

    I have tested the tps (even after replaced) with a known working unit with no change

    I have tested all 4 injectors from a working unit with no change

    I have tested all 4 coils with a working unit with no change

    I have tested the ECU with a working unit with no change


  2. #2
    bscpaint's Avatar
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    Stupid question but did you drain the old fuel?

  3. #3
    Lol, yes several times, fuel lines, pump, pickup and a injectors were all cleaned out twice

  4. #4
    shrabber's Avatar
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    Ok here's my 2 cents I don't know much But I will act as if it was a motor in the shop.

    you got good compression, what Your demonstrating by putting the ski in the water is the same thing as putting a car in drive, your putting it in Load at Idle.

    so, your plugs are black ( your obviously running rich).

    go back to basics, Your getting fuel and plenty but something( electronically) is telling the motor to increase the fuel hence it idles and runs fine on hose or out of water( no load)

    so.. Find out where the ignition is lacking, causing either Your timming to retard, decreasing Your spark. I assume its stock so... Start going back over connectors and sensors.

    you do not have a internal problem IMO Based off What You posted, sounds more like a faulty sensor, connection,harness etc

    just my opinion hope it helps

  5. #5
    porschemaniac's Avatar
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    Have you hooked it to a candoo or ydis to see if it gives you any codes? I've worked on a lot of mr1 motors that don't give a code on the cluster but will show a sensor code on the candoo or ydis. The ydis works better for me on these than my candoo. It pinpoints the issue better. I had one that drove me crazy (fxho). Candoo said bad idle bypass motor. Replaced it and ran for 15 minutes before repeating symptom. Put on candoo - same code. Put on ydis and stated bad IBM connection. Started checking connections and sure enough the large (24 or so ) main connector had one loose pin in it. Guessed it. One going to IBM. Could be something simple.

  6. #6
    Thanks shraber, I have not doing a full wire harness inspection. However, i did check all the pins that go into the ECU. Ill remove it and give it a full on test



    porche, i have the YDS first thing i did was hook it to this ski zero codes right now.


    I did replace the cam position sensor after it threw a code, but since doing that it has stopped. The machine ran a lot better afterwards. However, i will try it with an other working CPS

  7. #7
    Hot_Water's Avatar
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    kwtony, I don't know much, but would it be possible that one of the cams jumped the timing chain one tooth? I know the skis rev up pretty high when they break contact with and leave the water then the revs drop abruptly when they make water contact again. A cam timing one tooth off may allow the engine to rev, but with little available engine torque.

  8. #8
    Not ever going to lie, i was sitting in bed two nights ago and thought that exact same thing myself. An old chain or bad guide could maybe possibly cause it...it would certainly be a first for me. But i think this ski has been taken apart before, there are some things that arent factory and have me concerned. Considering the low hours on the ski, they shouldn't have been done and it was possibly by someone that didn't know what they were doing...i only know a few people that even know how to properly fix the timing on jet ski motors down here, luckily im one of them.

    ...Its been a nasty past few days for weather but, Im going to go there tomorrow and check it out. Thanks for the suggestion.

    Ill post the information i come up with.

  9. #9
    Hot_Water's Avatar
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    Maybe pull the tensioner plunger assembly from the head and see if it moves freely and has good tension?
    Last edited by Hot_Water; 09-14-2014 at 07:42 PM.

  10. #10

    If your still around!

    Quote Originally Posted by kwtony View Post
    Not ever going to lie, i was sitting in bed two nights ago and thought that exact same thing myself. An old chain or bad guide could maybe possibly cause it...it would certainly be a first for me. But i think this ski has been taken apart before, there are some things that arent factory and have me concerned. Considering the low hours on the ski, they shouldn't have been done and it was possibly by someone that didn't know what they were doing...i only know a few people that even know how to properly fix the timing on jet ski motors down here, luckily im one of them.

    ...Its been a nasty past few days for weather but, Im going to go there tomorrow and check it out. Thanks for the suggestion.

    Ill post the information i come up with.
    Did you ever figure this out? And I would love to talk to you about some issues if you are still on forum.

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