2000 Seadoo GS Shuts off Randomly While Cruising or Idling

[solracmd]

New owner of PWC's and loving it. Bought this one along with a 2011 GSX 130 in mid August last year and remembered the 2000 GS behaving like this a little bit. Good battery, fuel (have not refilled yet) seems fine (no rough idle or acceleration). Have taken it out 3 times so far this season. Pretty handy with engines just not familiar with rotax yet. Performed winterization, changed plugs, removed/reinstalled battery. Starts fine (with proper choke initially) then warms up and moves like a bullet. Can feel a bit of stuttering while at higher rpms at times (suggesting it might cut off at low idle). When it shuts down completely like it is abrupt like something electrical. Some threads I have seen suggest I should check ground wires but, not sure exactly where to look. I follow the negative wire from the battery and see it disappear on the one side of the engine. Reading other posts I see that I can get to the mpem (I guess thats what it is) when I remove the storage bucket under the front hull cover. I can also see a variety of wiring harnesses/connections (some dangling more than others). Thanks in advance for any and all your help and sorry if some of my descriptions are introductory. Trying to learn as much as I can.

[Myself]

Try to remove and reconnect the large connectors at the MPEM a couple times. A bit of corrosion or moisture could cause that. Usually it's a bad DESS key post which are available aftermarket.

[solracmd]

Thanks for the reply. I will proceed with your suggestions and let you know how things go.

[solracmd]

Oops. Forgot to ask. How hard is it to replace the DESS key post? I dont mind replacing something that makes sense. Also, any links on where to purchase would be great. Thanks in advance

[solracmd]

So, here is the latest. I wiped down the DESS key and post as well as, rubbed an eraser on the contacts (which did not seem to do much, it was pretty clean). Then, I unplugged and replugged the large connector at the MPEM. When I went for a ride the condition seemed to get worse with almost some rough idle/acceleration. Went back to dock. Unplugged and replugged, condition seemed to clear up (I wonder if I actually did not plug it back in fully since I have never unplugged any connectors since I purchased the ski). After a good 5 to 10 min ride (with bouncing around) the condition came back and would shut off abruptly. It restarts immediately (as always) and, then behaves similar to beginning with random cut offs (with durations in between that I experience no issues.. accel fine... hits 45 easy). I go back to dock unplugged and replugged, condition seemed to clear up again.

Thoughts on next steps? ... Should I purchase a new DESS key post and remove that from the equation?... Unplug/replug any other connectors (including possibly spraying with an appropriate cleaner for electrical contacts)? .... Other action(s). Thanks in advance for feedback everyone

[Myself]

Buy a new DESS post first and go from there.

[solracmd]

Just wanted to followup with an update. Bought a DESS post (three wire) on eBay for $55 and was not to bad to install. Loosened handlebar cover by removing 4 screws, could pry open to see wires. Then removed DESS post nut with some needle nose and popped out old post and cut wires. Spliced new post with wires, reinstalled and taped/tucked everything back into steering column. Ski started up fine (as always) but, did not cut out at all (this was an improvement).

Apparently the DESS post definitely fixed the random shutoffs experienced. However, very rough idling and acceleration. Decided something was up with the firing (hmmmm spark plugs). Replaced spark plugs and it appears all is back to normal. Running like a bullet today .... wooohooo!!! Hopefully this is my last post on this issue. Still some summer left so good riding to everyone!!

[Myself]

Glad to hear the result.