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Polaris MSX 150 - IFB

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  • #16
    Re: Polaris MSX 150 - IFB

    I just acquired a 2004 MSX 150 that hasn't been run in over 2 years. It is in nice shape with 269hrs on it. I would think for a 4 stroke that is about 1/2 life. I am well experienced on Genesis Ficht as I have 2 of them that run great but that is a story right there. I know the MSX is a different animal but does share a few things from the Genesis. Fuel pump is one of them. The guy i purchased it from said it has two issues of won't rev above 3500rpm and won's shut off. So I assume the SIFB is shot. I have not bypassed it yet to see.

    Does the SIFB die in sections or completely? It seems on mine, they auto off works because in 2 minutes you hear clicking as stuff powering down and putting the ski in neutral it idles down and doesn't runaway with itself on the trailer.

    Has anybody successfully fixed a dead SIFB? It looks like a circuit board attached to a 8 pin Delphi connector submerged in a 1/2 inch of epoxy. Mine actually has a 100uF 16v can capacitor poking through the epoxy. This would be like digging ancient ruins so you didn't damage the circuit board with a Dremel. On mine anyway, the epoxy doesn't seem too hard as I started scrapping away with a screw driver.

    I never leave the lanyard in any of my skis so that function I don't care about. I am careful enough not to gun it while in reverse, however, I would like to be able to put it in neutral when trailer testing on the hose so it doesn't over rev. I was thinking of designing a circuit with a 555 timer and a couple gates. I could give all 3 functions back. I would need to think about how to disable the 2 min auto shutoff for DW.
    Last edited by waves; 10-14-2020, 08:26 PM.


    • #17
      Re: Polaris MSX 150 - IFB

      I see 2 broken transistors. This would make sense since it won't shut off and is stuck in Reverse limit.

      Click image for larger version

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      Last edited by waves; 10-15-2020, 05:32 PM.


      • #18
        Re: Polaris MSX 150 - IFB

        I have successfully fixed this module!!! Believe it or not, I robbed the transistors and a diode out of an old harddrive. I replaced the two broken transistors and resoldered in U1. I tested and the reverse limit worked again but it wouldn't start. There was zero volts on pin C. I then found a cracked protection diode off of pin C the Ignition line.

        Any ideas on sealing this again? I want it in a water proof box.

        If anybody has any dead ones of these, PM me and I will try and fix them.