1996 Seadoo Speedster starboard engine dies

[kj_burr08]

Hi I'm having a little trouble with this boat. I bought it on a whim last year and it was said the engine on starboard was rebuilt but I seem to be having the most trouble with it. I'm cruising along the lake full throttle and the thing dies. I try to start it back up and it sounds congested (water maybe?) very hard to turn over but it does turn over. It won't start back up until the plugs are taken out it seems and cranked over. No water comes out of cylinder holes when cranking. Although I tried this after getting the boat back home 10-15mins of being shut down. When it does fire back up it spits a bunch of water out of exhaust and stalls, then it starts back up (a little rough at first).

So I can't figure this thing out happened twice now and worried the motor is about done. Compression was right around 130 but much lower after the motor dies (strange).

The other engine runs fine the whole time and is what got us back to shore. We only ran 1 motor back to shore at low speed (read somewhere to not throttle up on one motor alone).

Hoping to enjoy the summer a little bit with this thing, wasted a whole weekend already.

Any ideas?

 

[kj_burr08]

I've searched the forum for this issue but can't find anything.

Have to get a new compression tester the current one stopped working.

Maybe I should take spark plugs out as soon as it happens on the lake? Don't really want to keep running it like it is though.

 

[mikidymac]

It sounds like it’s seizing. Did you rebuild the carbs with genuine mikuni parts?

 

[kj_burr08]

The guy I bought it from said carbs were all rebuilt. That engine was re-bored, shouldn't it have higher compression for being rebuilt? I'm guessing this is why the engine had to be rebuilt lol.

 

[kj_burr08]

Well took it to the lake again today. It ran good about 5 mins (usual) full throttle, then motor just dies and wont start back up. Motor seemed a little hotter than port side motor. Didn't have spark on one coil either for a little bit. (Might of been both coils I had helper so was going by what he said)

Putted back to shore on one motor and got it back up on the trailer. It started again a little rough at first then clears back up and is normal again. Dipped it back in the water and it ran so we took it back out again.

Back up to full throttle again and both motors die at the same time, think it was the lanyard. Took key off and on again, port motor starts up, and starboard motor won't start back as usual (this is after dieing at full throttle).

So we take the spark plugs out it's a grayish brown I guess and dry (probably normal). We didn't test for spark but I'm guessing it was the same as before. We head back to shore.

We get it back up on the trailer, after a little bit of cranking it starts back up again...

We tried reserve tank runs fine in neutral (haven't tried running it fast that way), and on position.

Could it be getting to hot and shutting off the coils? Maybe not enough water flow through the motor? The overheat buzzer doesn't sound. We swapped the thermostat between motors and buzzer never did sound.

The motor dies instantly when it shuts off, so I'm leaning toward something electrical or maybe seizing.

 

[kj_burr08]

Updates I pulled the motor out and got the carbs off. Looks like there was water intrusion. Rust in a lot of places. Can water intrude 1 motor and not the other? Guess I will be ordering carb kits soon. Sending from a tablet I will update post later with pictures.

Edit:
Added some pictures.
Could this cause the seizing? Are there steps to take to clear water from the fuel system and prevent it from happening again? How does water get in there anyway?

I'll search around for some possible answers but if anyone has any info I'd really appreciate it. Would love to get this going by next weekend!