1997 Gtx mpem help

[sam s]

Hi Everyone ,
my 1997 gtx 787 up and quit with no spark what so ever . Diagnosed by seadoo tech that the MPEM is toast . I have read previous posts regarding a 5amp fuse problem and mine did not blow any fuses at all . I have also read of a possible silicon control rectified somewhere on the motherboard in the MPEM going bad . Does anyone have any insight or expertise on these mpem's ? my unit number on the MPEM is 278-001-133.
any help would be amazing

Thanks,
Sam S

 

[JeremyD615]

There is a protection diode in the MPEM that goes bad when it is blowing fuses. That doesn’t sound like the issue here though. Several people have tried to melt the epoxy out of the MPEM and repair components, but I haven’t seen many do it successfully... I would either give Westside Powersports a call, as they keep good used MPEM’s on the shelf, or roll the dice with an aftermarket one. Several people have had issues with aftermarket units being dead on arrival, so if you go that route, be prepared to have to send one back if it’s defective...

 

[sam s]

Thanks Jeremy . I appreciate the info and will definitely give Westside a call .

 

[Ckrawiec]

Hi Everyone ,
my 1997 gtx 787 up and quit with no spark what so ever . Diagnosed by seadoo tech that the MPEM is toast . I have read previous posts regarding a 5amp fuse problem and mine did not blow any fuses at all . I have also read of a possible silicon control rectified somewhere on the motherboard in the MPEM going bad . Does anyone have any insight or expertise on these mpem's ? my unit number on the MPEM is 278-001-133.
any help would be amazing

Thanks,
Sam S

Can you back up the trolley.....what does the ski do or doesn't do?

Assuming you are starting with a good strong battery installed in the ski:
1) does the ski wake up if you hit the S/S button once? - with no DESS key installed
2) if the ski wakes up and you install your DESS key, does the ski beep-beep at you?
3) if that happens...what happens when you push and hold the S/S button? do you here the starter solenoid click? does the ski /starter attempt to crank?

 

[sam s]

Good day Ckrawiec,
I have a new battery load tested all good , the seadoo cranks over no problem , the display lights up no problem , clipped back the plugs in case was spark plug wires , still no spark . the seadoo tech did the tests to the mpem and informed me it is no good . To be honest , I have no idea how to test it myself . But we did temporarily switch out the mpem from another running 97gtx and mine fired right up and didn't miss a beat so I would have to assume something fried in my mpem .

 

[mikidymac]

Don't bother with the aftermarket ones.

For a tested and guaranteed used one contact Nick or Jess at Westside Powersports.

 

[Ckrawiec]

Ok then....your mpem puts out the voltage on the WHITE wire to the ignition coil...both cylinders fire at once (if they fire).....YOU have ruled out the ignition coil first? - although you've swapped mpems and she fires up.....hmmmm....I'm surprised that she's cranks over with your old mpem....that would have tipped me off that the mpem is working but if there is no voltage on the white wire to the ignition coil....you is dead/no spark.

On your existing mpem....are the fuses good? should be a 5 and 15 amp....just going through all the normal checks (in my brain) before I dive into the mpem....I always do cheap checks and parts first....BEFORE I start spending any real money....that's just me though.....

AS far as a fried piece of the mpem....there is a diode on the board that goes.....some have apparently located and replaced that part (couple bucks)...but is there a tried and true method....can't say that I know it

 

[sam s]

With my existing mpem there was no spark to either plugs , no fuses were blown either in terms of 5 and 15amp. I have heard the same thing regarding the possibility of it being a diode but that I am told will blow the 5 a fuse indicating it is the diode , I have also heard of an apparent Motorola silicon control rectifier buried somewhere in the board that could be the culprit. I would have to agree that I would love to be able to fix and get up and running cheaply if possible .

 

[JeremyD615]

Like I mentioned before, there have been some that have dug into these things and replaced components, but it involves melting the epoxy that everything is potted in and cutting it away enough to desolder the component from the PCB, and then resoldering the new component in... If you’re an experienced electronics technician, it’s very doable, but for most of us, it will be worth saving the frustration and buying a replacement...

 

[Ckrawiec]

With my existing mpem there was no spark to either plugs , no fuses were blown either in terms of 5 and 15amp. I have heard the same thing regarding the possibility of it being a diode but that I am told will blow the 5 a fuse indicating it is the diode , I have also heard of an apparent Motorola silicon control rectifier buried somewhere in the board that could be the culprit. I would have to agree that I would love to be able to fix and get up and running cheaply if possible .

SO, you have ABSOLUTELY verified that you have NO voltage on the WHITE wire out of the old mpem to the ignition coil while the ski is cranking/turning over? If so, I see no other viable option but to go with a "new" (good used maybe) mpem.

If you had voltage on the WHITE wire, but still no spark to the plugs ...that would point to the ignition coil and/or the spark plug wires themselves.....(and your ignition coil is grounded to the battery and the solenoid is grounded to the ignition coil (all checked, etc...)

Lastly.....the only two things left after that are the spark plug boots themselves and the plugs themselves, the boots need to be a "resistive" type, and the spark plugs are specific to the ski.

Just trying to rule out all possibilities here....