Engine cuts at 35mph

[Brendan97]

I have a 2001 gti with the 717cc engine in it. I blew the diode in the MPEM so I bought an Ebay special replacement and everything is happy. Starts great and runs great. But if I go full throttle or creep it past about 35mph I get 2 beeps and the engine dies. But touch the start button and it fires right back up. I've cleaned the DESS key. And nothing is loose. I had it out in chop today and if I kept it under 35 it ran flawlessly.

Not sure where to go from here... I dont have any blown fuses..

Any help is greatly appreciated

 

[Ckrawiec]

Need the background....so new aftermarket MPEM.....came with new DESS keys or not? If not, you had your old keys programmed to the new mpem?

Obviously, the ski starts and runs....so I'm curious how that happens with respect to the DESS key and the new mpem.

 

[Brendan97]

The MPEM did not come with a key. Was advertised as "universal - no reprogramming required"

I'll ask the dumb question, how would I go about reprogramming the DESS key

 

[Ckrawiec]

The MPEM did not come with a key. Was advertised as "universal - no reprogramming required"

I'll ask the dumb question, how would I go about reprogramming the DESS key

Interesting......so the mpem is universal (whatever that means)...which probably means there are no security features, so DESS is not even there (in the mpem)....do you even need to plug a key into the ski then to start it???? A DESS key communicates with an OEM MPEM....the key has the chip and the MPEM has the memory of that chip.

There are no "dumb questions" here...nobody knows everything...well maybe nobody...but we are all seeking answers to questions about things we don't know...so always ask.

YOU can't reprogram a key [the key is not programmed btw, the MPEM is] without special software and a CanDoo programmer, I believe....but now why would you need to do that if the mpem doesn't even have DESS features. Did the mpem come with an instruction manual about the features it does contain and what the beeps would mean?

 

[Brendan97]

Not sure, got it off ebay, put the key on it. It beeps twice and starts. I pull the key off and it stops.

Sea Doo MPEM CDI Box 717 720 GS 1997-2001 97 98 99 00 01 | eBay


^^^ that's the link to the part I purchased

I was reading up on the owner manual and it seems like it could be going into "limp mode"Wont go past 4500rpm (35ish mph) could the MPEM be faulty? I can still return it.

Interesting......so the mpem is universal (whatever that means)...which probably means there are no security features, so DESS is not even there (in the mpem)....do you even need to plug a key into the ski then to start it???? A DESS key communicates with an OEM MPEM....the key has the chip and the MPEM has the memory of that chip.

There are no "dumb questions" here...nobody knows everything...well maybe nobody...but we are all seeking answers to questions about things we don't know...so always ask.

YOU can't reprogram a key without special software and a CanDoo programmer, I believe....but now why would you need to do that if the mpem doesn't even have DESS features. Did the mpem come with an instruction manual about the features it does contain and what the beeps would mean?

 

[JeremyD615]

Yes, the aftermarket MPEM’s are universal, as in they will start as long as a DESS key is present. The factory OEM MPEM units are like that when new as well. They are universal until the first key is programmed to them, and then they become forever locked after that... It sounds like you have an issue with the wiring between the DESS post and the MPEM somewhere. Go through and check the wiring and clean/reseat any connectors and see if that does the trick...

 

[benjilafouine]

Whatever it is this is not an original OEM part. The description says so clearly. It also says that you cannot plug a diagnostic tool in it as well so I assume that a key cannot be programmed. The unit could be faulty but I doubt the DESS post on your Sea-Doo has become defective just like that. A faulty DESS post will usually be more unpredictable than this (I have a GTI LE 2003 and it happened to me).

You didn't mention how your MPEM blew in the first place. Maybe something else blew at the same time?

 

[JeremyD615]

I’ve seen intermittent issues with the posts that act like this before. They usually are much more unpredictable than this, but not always... Checking the wiring costs nothing more than a few minutes of time, so that’s where I would start.

Your other possibility is a loose ground in the E box. Sometimes resident frequencies will cause them to move around just enough to break the circuit...

 

[benjilafouine]

Oh, I agree totally with the wire checking portion. I would start with that too to rule out this possibility. However, we are dealing with a cheaper aftermarket part and that remains a fact too. An OEM part is much more predictable IMO. Maybe the OP can't afford a brand new MPEM and the programming that goes with it and I understand that. I just bought a CanDoo Pro and here in Canada, it just cost me $600.00 Canadian dollars. I could most likely add a new key if I already had one but it is unclear if I could start from scratch with a new OEM MPEM.

But once I lost both my keys (small compartment was not closed correctly) on my 2 stroke and the dealer reprogrammed two new ones for me in a snap.

 

[JeremyD615]

I used to be totally against the aftermarket MPEM’s myself, but I’ve noticed that almost all of the complaints I’ve seen are for them being dead on arrival. I haven’t heard of many failing once they’re installed and running... I’ve got an aftermarket one in one of my skis that was put in as a temporary fix so that I could send my original one off for programming, and it’s run well, so I never swapped the stock one back in.

Don’t take that as an endorsement for aftermarket ones, because it’s not. I think it’s always better to keep the OEM one if possible. I’ve just come to the conclusion that it’s not as terrible a gamble as I originally thought....

 

[Brendan97]

I lent the ski out to a buddy who killed the battery. instead of pulling the battery, charging it and putting it back in. He used a booster pack on it to try and start the ski.. "a few times" after that it just blew fuses as soon as the battery was connected. I'm 22 and trying to put myself through university... definitely not really wanting to shell out $600. Paid $200 tax in for the aftermarket one.

Not going after my buddy for the money to fix it. Gunna say that now. Not my style.

 

[Ckrawiec]

I lent the ski out to a buddy who killed the battery. instead of pulling the battery, charging it and putting it back in. He used a booster pack on it to try and start the ski.. "a few times" after that it just blew fuses as soon as the battery was connected. I'm 22 and trying to put myself through university... definitely not really wanting to shell out $600. Paid $200 tax in for the aftermarket one.

Not going after my buddy for the money to fix it. Gunna say that now. Not my style.

You are a good friend and have learned a valuable lesson...don't lend out your stuff . I'm sure it was totally unintentional on his part, obviously not knowing to try to jump start skis (although I've done it myself (not often)) - but I accept the risk and it's my ski.

Question is -> how did he "kill" the battery? Sounds more like the ski is/was in a state of distress (since the inner workings of the ski are supposed to keep the battery charged while running). If he killed the battery because the ski wouldn't start, then that is a separate issue -> why won't it start (and that is a much more complicated question/journey).

Good luck in school....I TG (thank goodness) that all my kids are FINALLY done with college/university !!!!

 

[Brendan97]

He was trying to start it with the fuel off....

He is new to this sport... but you cant learn if no one gives you the chance

You are a good friend and have learned a valuable lesson...don't lend out your stuff . I'm sure it was totally unintentional on his part, obviously not knowing to try to jump start skis (although I've done it myself (not often)) - but I accept the risk and it's my ski.

Question is -> how did he "kill" the battery? Sounds more like the ski is/was in a state of distress (since the inner workings of the ski are supposed to keep the battery charged while running). If he killed the battery because the ski wouldn't start, then that is a separate issue -> why won't it start (and that is a much more complicated question/journey).

Good luck in school....I TG (thank goodness) that all my kids are FINALLY done with college/university !!!!