Yet another MPEM call for help :)

[curtisr]

Hi everyone,

Summer's here and although the spirit is willing, perhaps my MPEM is weak??? The engine will run for 2 minutes and then quit. Yup, the plugs are wet. Here's what has been determined so far:

1. checked spark on left and right motors, okay
2. compression on both motors -- 150 mag, 150 pto, 150 psi
3. spark plugs wet
4. started both engines (garden hose):
   1. passenger side engine was running and then stopped, pulled plugs, unit has no spark
   2. stator reads 0.2 ohms
   3. charge coil reads 56.7 ohms
   4. checked primary ignition coil, okay
   5. checked secondary ignition coil, okay
   6. after testing unit the spark returns
   7. ran motors for about 2 minutes then stopped -- no spark

Consclusion? MPEM has a module that's cuttin gout the spark and shutting the unit down???

Any suggestions as to my next step would be greatly appreciated! Thanks everyone!

Roger C

 

[mikidymac]

I know Westside Powersports Seadoo did a lot of work on these and might be able to help if nobody has ideas. I really haven’t done much with the boats.

 

[dklswh]

Hi everyone,

Summer's here and although the spirit is willing, perhaps my MPEM is weak??? The engine will run for 2 minutes and then quit. Yup, the plugs are wet. Here's what has been determined so far:

1. checked spark on left and right motors, okay
2. compression on both motors -- 150 mag, 150 pto, 150 psi
3. spark plugs wet
4. started both engines (garden hose):
   1. passenger side engine was running and then stopped, pulled plugs, unit has no spark
   2. stator reads 0.2 ohms
   3. charge coil reads 56.7 ohms
   4. checked primary ignition coil, okay
   5. checked secondary ignition coil, okay
   6. after testing unit the spark returns
   7. ran motors for about 2 minutes then stopped -- no spark

Consclusion? MPEM has a module that's cuttin gout the spark and shutting the unit down???

Any suggestions as to my next step would be greatly appreciated! Thanks everyone!

Roger C

i would trim your spark plug wires first.

 

[curtisr]

I know Westside Powersports Seadoo did a lot of work on these and might be able to help if nobody has ideas. I really haven’t done much with the boats.

Yes, they're great. Thanks!

 

[curtisr]

i would trim your spark plug wires first.

Neat. How so?

 

[dklswh]

Neat. How so?

the boots screw on to wires just take off and cut quarter inch and screw back on

 

[curtisr]

Of course, silly me. Thanks. Will try.

 

[2x2smoke]

which boat do you have? I'm working through a DESS circuit issue at the moment. Its possible your mpem thinks that the lanyard is being pulled and its doing you a favor by killing both motors

Seadoo challenger random stalling / intermittently cuts out

 

[curtisr]

which boat do you have? I'm working through a DESS circuit issue at the moment. Its possible your mpem thinks that the lanyard is being pulled and its doing you a favor by killing both motors

Seadoo challenger random stalling / intermittently cuts out

Silly me. I forgot to add that the boat is a 1997 BRP Speedster.

 

[2x2smoke]

So you can reboot the system and it will start but only stay running for 2 minutes, then both engines shut off. Then you do the ritual again and get the same results?

Are you getting any beeps?

I think the mpem only shuts the motors off if it thinks the lanyard has been pulled. The DESS circuit needs to stay grounded to indicate the lanyard is attached. Any bad connection will interrupt the ground condition. There are 4 connections between the mpem to the dess and back to the mpem. There's also the actual dess switch and the actual ground wires from the mpem to the battery negative terminal. So that is about 8 places your ground signal can be interrupted to kill your motors in the name of public safety

the video i posted shows a technique to trick the mpem into not seeing a fleeting interrupt event.

 

[curtisr]

So you can reboot the system and it will start but only stay running for 2 minutes, then both engines shut off. Then you do the ritual again and get the same results?

Are you getting any beeps?

I think the mpem only shuts the motors off if it thinks the lanyard has been pulled. The DESS circuit needs to stay grounded to indicate the lanyard is attached. Any bad connection will interrupt the ground condition. There are 4 connections between the mpem to the dess and back to the mpem. There's also the actual dess switch and the actual ground wires from the mpem to the battery negative terminal. So that is about 8 places your ground signal can be interrupted to kill your motors in the name of public safety

the video i posted shows a technique to trick the mpem into not seeing a fleeting interrupt event.

2x2, you'd be right at home in the Porsche World! What's the first recommendation when one posts a new-to-them acquisition? Clean the grounds! Got an electrical gremlin? Clean the grounds!!!

This is exceptionally useful -- as is your video -- thank you. We put the boat away this past weekend and won't have access to it until later July. At that point, I'll report back. Thanks again.