Need some help to troubleshoot.

[Cdn20valve]

1998 seadoo speedster 1600
Twin 787. Had it on the water twice. Both times, I've had the same issue.

Running on the water, both engines quit after about 1 hour. Let it sit for a couple minutes, engines restart fine, than turn off again a minute later. I eventually limped it back to the dock, and took the boat home.

At home, I ran both engines on the hose. The starboard engine ran for 5 minutes on the hose. No problem.

Port engine stalled almost immediately after turning on water.

Things I've tried:
Rebuilt port side carbs (incl replaced carb filters) one was very dirty!
Swapped spark plugs from engines
Swapped fuel pump(external on this model)
Inspected coil box, no corrosion, no loose connections.

I noticed the port side plugs looked really oily, this is why I suspect a fuelling issues.

Thanks guys.

 

[dbracela]

Do you know the compression readings?

 

[Cdn20valve]

135 and 140 with throttle closed lol.

 

[Cdn20valve]

I noticed no fuel squirts out of one of the accelerator pump nozzles. Like it's plugged. Could this cause the stall? When does the accelerator pump start to spray fuel?

 

[dbracela]

Dr. Honda is the carb guru, maybe he'll chime in.

 

[Sportster-2001-951C-Stock]

I noticed no fuel squirts out of one of the accelerator pump nozzles. Like it's plugged. Could this cause the stall? When does the accelerator pump start to spray fuel?

The accelerator pump sprays fuel as the throttle is advanced from idle to part throttle. It could be the accelerator pump isn't able to pull fuel from the carb b/c the carb is dry, or it could be the spray nozzles are clogged with fuel gum.

You can try blowing some compressed air through the nozzles, WD-40 or carb cleaner can connected to the nozzle is another possibility if you don't have compressed air.

DON'T spray carb cleaner into the accelerator pump or internal the rubber diaphragm will be ruined!

 

[Cdn20valve]

Ok. Thanks for the info. The engine is stalling at idle, so I guess the accelerator pump, is not too blame. I'm starting to suspect mpem issues here, which is my biggest fear. I'll tell you why;

The port side tach is intermitent, at start up it never works. The tach itself is good, i swapped tachs to confirm. When the tach is inop and the engine running, the start/stop button thinks the engine is off, and will engage the starter if pressed, that tells me that the mpem is not seeing rpm signal.

However, in the water after several minutes of cruising the tach started working. But it would cut in and out, when it did, the engine would skip a beat each time. I'm not sure if this is related to the stalling, but I thought I should mention it.

Note, at one point, the tach was showing 1000 rpm at idle, and every time I revved the engine, the tach would go to 0rpm. I just have This feeling all this is related. As when the engine cuts out, it doesn't sputter, it more like an electrical shut down.

THanks for taking the time to help me out.

 

[Cdn20valve]

Success!! I cleaned out the accel pump nozzle with compressed air.
I also found a pin hole leak in the exhaust, spraying right into the stator assembly.
The tach works now, and engine runs. Could this have been the problem this entire time? I'm going to go have a beer.

 

[jeffbeckib]

could you tell me exactly what you did? I'm having a similar problem with my starboard motor cutting out at Idle, runs fine when I give it throttle, but at idle, it just dies. I can't find any part called accelerator pump nozzle

thanks