97 Seadoo Challenger 1800 Both Engines Shutting Off


New Member
I just got my boat back from the shop to fix a minor issue and now I'm getting a problem I have never had before. I brought it in to the shop to the bilge pump replaced, there was an issue with the wiring as it would not turn on automatically or with the switch. They also found a temp sensor that they replaced as well. When I received the boat back I started having an issue as soon as I launched it. It appears it could be an electrical issue as both motors will die at the same time, similar to a kill switch being pulled. I know knowledgable in two stroke motors but electrical is not my forte and this one has stumped me. I'll post some things below that I have troubleshooted to narrow it down.

I thought it was the battery so I replaced it with a brand new one didnt fix the issue. I had a new key made last year, I went and put the old key on that I never had issues with and it was still happening.

Typically what happens is I can get both motors started and running. As soon as I began to give it throttle both motors will shut off and sometimes I'll get two beeps, one beep or nothing at all. When I first got it back from the shop I thought it was just a dead battery so I was able to run it at slow rpms and I just kept increasing the RPM's until I finally got up to full speed and it was fine. I thought it was fixed. I put the new battery in after and it worked great no issues. Then I brought 2 people down to the boat the next day and the problem had returned. I tried it again today, I can literally have it in neutral on the dock and when I give it throttle it will shut off, its not consitent though, sometimes I was able to hit the rev limiter a couple times and it would run for a minute before cutting out.

If anyone has any insight that would be great. I'm not sure if there is a short somewhere that is causing it to shut off but not blow a fuse? or if the motor has a sensor to shut off when there is a misfire and I just need to change the spark plugs and the fuel? its the same fuel from the winter with stablizer in it. I had to pull out a spark plug the other day and it was perfect brown color.

I also attached a photo of the battery before I changed it. On the positive there is the main line and a green line which they have run to the bilge pump. On the negative there are two thick black cables, a thin black cable just like the green one and there was one white cable you can see there that was severed off. Not sure if that was from the old bilge pump or not but I just took that off when I replaced the battery.


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There are no sensors that shut off the engine.

If they hacked into the wiring that is where I would start.
My engines WILL shut down if they get too hot. I wonder if they will run with the head temp sensor disconnected?

1996 Speedster with twin 720s.
Interesting, I just thought of something, it may die when the motors are cold. I dont know if that would make sense for a temp sensor? but there could be a correlation to it being cold and not triggering the shut off. They hacked some of the wiring to put in the new bilge pump so i'm wondering if theres some sort of short there that could potentially be causing the problem.
My boat came with a factory bilge setup with it's own wiring. If I were to replace the pump, I would use the factory wiring.

Why would a replacement pump require hacking the existing wiring?
That temp sensor is just an alarm, it has nothing to do with shutting the engines off.