1995 Seadoo SPI will not shut off

[jetwrench604]

I have a 1995 Seadoo SPI with the white 587 engine. I am having an issue where the only way to shut the ski off is to choke it out becuase neither the handlebar stop button nor the lanyard saftey switch cuts the engine off. I searched this forum and only found a few posts where others were experiencing the same issue.

Troubleshooting I have done so far:
1.) I checked for proper continuity of the wires between the MPEM and the handlebar stop switch when its being depressed. That checked out good.
2.) I also checked for proper operation and continuity of the lanyard stop switch which also checked out good. One other way I know this switch is operating properly is that to start the ski, you must have the lanyard switch depressed.
3.) Checked that all MPEM fuses are good.
3.) Based on these findings, I assumed it was a bad MPEM. I bought the same P/N MPEM on ebay and just swapped it out but it did not fix the problem.

I'm hoping someone has seen this issue before and might be able to give me guidance on what else to try.

Thanks in advance.

 

[POPPS]

, disconnect the connector coming from the start stop switch under the hood,,,that way,,,you may be able to better zero in why the kill switch is not activating,,,sounds like the pulse line in the cdi may be shorting,,,an electrical diagram will be very handy for this,,just some ideas,,,am not an electrical wizard,,,you should be able to “ground out” the cdi trigger pulse,,

 

[jetwrench604]

That’s a good idea. I do have a wiring diagram. Let me post it and see if we can figure out which wire I can try to manually ground out the trigger pulse.

 

[jetwrench604]

I hope this shows up clear.

 

[POPPS]

Unfortunately not clear on my cheap iPad,,,the trigger sends a pulse to the cdi…the cdi sends a signal to the coil to fire the plugs…the start stop switch grounds out the cdi signal,,,like in a lawn mower etc…seems like the MPEM will not groundout the signal at the cdi…let us know…there are far better electrically inclined guys out here,,,Miki the moderator is very experienced.

 

[jetwrench604]

Attached a PDF copy. Maybe this will look better.

 

[POPPS]

Think I have it backward,,,the lanyard “
should close the cdi circuit to send a signal to the coil.,,apologies,,

 

[jetwrench604]

Yes. The handlebar stop switch is normally closed and the lanyard safety switch is normally open. Any one of these switches will cut the ground to the MPEM, thus removing the signal to fire. what’s so weird is that have checked continuity and both switches operate properly. I even disconnected them from the MPEM and was able to get continuity from ground to the spot where it enters the MPEM.

I thought a new MPEM would fix it. Anyone thinking I have the kind of luck to have bought a used MPEM with the exact same problem? LOL !?!???!!

Im still trying.

 

[jetwrench604]

Can anyone explain the abbreviation on this wiring schematic where it states, “NO/JA”. Directly under this it reads, “RD/YL”. Clearly the latter is the wire color RED with a YELLOW stripe but what is the former? Is this potentially a wire color code in another language? I’m wondering if the NO has something to do with normally open?

 

[POPPS]

The yellow with the red tracer is the start stop switch,,,maybe the relay is the culprit?

 

[jetwrench604]

The yellow with the red tracer goes to the start relay from the MPEM. It starts fine so I'm thinking it has more to do with the circuit that runs through the handlebar STOP button and the safety lanyard.

 

[jetwrench604]

I must have the wrong wiring diagram because you are correct. The wire coming from the handlebar switch is yellow with a red strip but the wiring diagram I found in the manual shows it being a black with yellow stripe.

 

[POPPS]

Well…I just got a 2001 Yamaha 700…that would not turn off,,,spent time in the electrical box,,,a huge shitstorm,,,and taking the key and start stop switch apart…and so presto,,,I thought there may be an air leak since there would be trace amounts of oil in the hull,,so,,pulled the motor,,,split the cases,,,,,,and low and behold,,,the outer pto seal was improperly installed,,,and the sealer for the cases was not sealing,,,in various places,,,now the Yamaha has different electrics,,,so,,,maybe you have an air leak at the carb base gasket,,,or the front or rear crank seals,,,just a thot outside the inner electrical box,

 

[jetwrench604]

If I just start shotgunning parts at this thing to try and fix it what would be everyone's best guess as to the most likely issue? I'm struggling to think its wiring since everything seems to be in tact and tight. No broken wires and the kill circuit is checking our VIA multimeter. I replaced the MPEM with no fix. Is it worth it to throw a rectifier at this thing?

 

[TheGTIjetguy]

Have you tried to kill it by pulling the plug wires when it is running? That will definitely take any sort of lean run-on or cylinder hot spot condition out of the picture. Then you know for sure it’s electrical.

 

[jetwrench604]

Yes. I did that a few times on the trailer and it killed it.

 

[POPPS]

When I pulled the plugs on my Yamaha it still ran,,,choking was the only solution…but yours stops when you pull the plugs,,,so it may not be a lean “auto ignition” situation
Can you open the Ebox…find the pulse wire from the front cover trigger coil,that goes to the cdi from the MPEM,,,,,it’s either yellow with white tracer,,,or black with yellow tracer,,,(can’t remember),,,start it,,,and then pull the connector that goes to the cdi,..if it stops,,,then that may help you,,,I am not good at electrics,,,but if you follow your schematic,,,this may help you,,,if you pull the pulse wire from the trigger, ,or from am mpem..it should stop for sure,,,
Just some notions,,,I am only familiar with my 96 Xp,,,

 

[jetwrench604]

I’ll try that but if pulling the pulse wire to the coils kills the engine, wouldn’t that indicate a bad MPEM? Again I already replaced it but no fix.

 

[POPPS]

How about the relay…start stop goes thru it,,,??,,,just trying to “remove” one component at a time that pulses the cdi and then your coil.,,?

 

[jetwrench604]

Where is that relay located?

 

[jetwrench604]

Are you talking about the starter solenoid? The black thing with the two big red battery leads on it? Its buried under all of the wires on the bottom right side of the above image. How would the starter solenoid affect the ability to stop the engine? Have you seen this before?

 

[jetwrench604]

I just realized that there is a Black/Red wire coming off of the MPEM inside the electrical box that was never connected to anything. So I left it unconnected. I assumed it was for the VTS system but was unused since I don't have it on my ski. However, after pouring over these wiring scematics, I'm thinking the unconnected Black/Red lead coming from the MPEM connects to the open Red/Black connection going to the coil. I'll attach a picture with red circles around the two wires in question.

 

[jetwrench604]

See red circled wiring.

 

[jetwrench604]

I'm wanting to connect these and see if it kills the engine but I'm afraid if my suspicion is incorrect, I could blow something and only deepen my layers of complexity. Anybody have any opinions?

 

[POPPS]

Now I get it,,,the cdi is in the other upper half of the box,,,I think the relay is there with the cdi…