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  1. #1
    superramjet's Avatar
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    Msx starts and idles great but wont rev

    I don't have a scanner, linkage appears to be working, just won't rev when I pull the trigger. Any ideas?
    Thanks Tom


  2. #2
    Kosh's Avatar
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    Hi Tom,
    Could be lots of things, can we have some history please?

    Cheers

  3. #3
    Redrum's Avatar
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    Is this the two stroke 140 or the four stroke 110/150?

  4. #4
    superramjet's Avatar
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    Thanks for the replies, Its the 4 stroke. I really dont have history, bought it at an auction, it was missing a computer, I bought a known working computer, put it in and a battery and it starts easy and and idles pretty well. I pull the trigger and nothing happens,just stays at idle

  5. #5
    Kosh's Avatar
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    Hi Tom,

    Does the light go out after 10 flashes?

    I guess you have checked all the connections are in place?

    I have seen the butterfly seize up from sitting so pull the hose of the TB and put your fingers down the throat and push, it will take some effort to move as it needs to spin the actuator motor over (mechanical advantage is the wrong way round)

    Try a quick jab on the stater button (with out starting) and have a listen to the TB it should make some high pitched noises. If not unplug connector and check for the green meany. By bad design the flush connection makes its way over the top of the throttle body and tends to deposit water over the connector.

    There are many starting points, this is mine, others will chime in with theirs and you will get it sorted.

    Happy hunting

  6. #6
    superramjet's Avatar
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    I will check and report back, thanks. Does an actuator motor open the butterflies? not mechanical? thanks, Tom

  7. #7
    Redrum's Avatar
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    Yes, the throttle body butterfly valve is drive-by-wire and run by an actuator motor. Like Kosh said, hit the stater and let go right away. You should be able to hear the motor running. If you have the intake piping off going into the TB you should see said valve moving when you bump the start button.

  8. #8

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    You need to get some smart guys involved here (Kosh,Martin,Jay etc), but you cannot just toss a new ECU into the system... The injectors usually need to be programmed to match the system, and the ECU most likely needs to be put the the "adaptive mode" to relearn everything. You dont need the diagnostics sofware to do this.. The PPU module could also be a problem, this will limit it to 1800 Rpm..

    THe Bosch diagnostics will tell you what the potential problem is by limiting the peak Rpm.
    For example 3400 -3800 Rpm is usually the IFB module, as the ECU thinks the boat is in reverse.

    I dont know much about this system, and possibly somebody else can help?

    Regards,
    Randy

  9. #9
    superramjet's Avatar
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    Didnt know I couldnt just put ecm in. Butterflys not seized, I saw it flicker open when I tried just hitting the start button, no corrosion on connector and I heard the high pitched noise that Kosh was talking about. Red light flashes and does not go out after 10 flashes, Display says service engine. Idles smoothly at about 2400 rpms. The butterfly flutters from engine suctions or vibration but doesnt open with trigger.

    I was thinking it could be the actuator motor but It revs high if you put it in forward and its not in the water, so it must work to open the butterflies.

    Why would it act different in forward in the water than out of water. Is there a sensor that shuts down the actuator?

    Any more things to check?, seem like a cable opening the butterflys like the hydrospace would be a better deal.


    Thanks Randy, I wanted to tell you that newer disc you sent me for the hydrospace worked perfectly. It was much easier to load and install than the first one.

    Tom
    Thanks Tom

  10. #10
    Kosh's Avatar
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    Hi Tom,

    If the throttle plate is not seized and you bump the start button with out starting the motor you can view the throttle plate through it entire range as you operate the throttle lever.

    If I understand correctly (and this is all out of the water) in reverse it is limited to around 2400 but you dont have any real throttle control? If you put the reverse lever in forward it revs to the moon and the throttle lever has no effect? If so this is completly normal! what I hear you say dont be stupid who would design an engine to do this! I would have been sorted if the model had of continued.sigh

    Now if it is doing the above put it in the water and you will be surprised it will all work normally.

    If this is not the case give us some more to work with, the more detailed the description the easier it will be for everone to diagnose.

    Cheers

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