Greetings PWC followers, I have a 99 Seadoo GSX 780CC EFI It goes like stink for about 4 minutes then dies out completely. It will start again and run really rough. I have checked compression, 150 psi in both cylinders, Bench tested the fuel pump, checked filters, plenty of spark with the new NGK plugs, put fresh fuel. Please help I really want to ride and I'm getting really tired of paddeling. Thanks
Baffled
- Thread starter DABOO
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y_not_ride
New Member
check the plastic filter in the front of the ski sometimes they crack when you put them on thats what happen to mine.
Plugs?
Take a plug wrench with you and as soon as it dies out, pull the plugs to read them. With the engine having a few years on it, it wouldn't surprise me if your tuned exhaust gasket at the top loop is leaking by. Here, the water jacket and exhaust system can come into contact with each other. If you run for 4 minutes and just die, that could be due to a lot of things, but your saying that you can eventually start back up and run really rough. Sounds like you might be running with water in the cylinders. At the moment, I'm ruling out the head gasket since your compression seems to be fine.
Read the plugs after it dies. Check for water on them. If you wait till you come back in, the heat of the cylinders can evaporate the water and you'll not see it.
Let me know what you find out. There are still other possibilities.
Take a plug wrench with you and as soon as it dies out, pull the plugs to read them. With the engine having a few years on it, it wouldn't surprise me if your tuned exhaust gasket at the top loop is leaking by. Here, the water jacket and exhaust system can come into contact with each other. If you run for 4 minutes and just die, that could be due to a lot of things, but your saying that you can eventually start back up and run really rough. Sounds like you might be running with water in the cylinders. At the moment, I'm ruling out the head gasket since your compression seems to be fine.
Read the plugs after it dies. Check for water on them. If you wait till you come back in, the heat of the cylinders can evaporate the water and you'll not see it.
Let me know what you find out. There are still other possibilities.
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Here's another possibility:
When it runs really rough, after it "goes like stink for 4 minutes" is it in limp mode with limited RPM? How does it run when just crusing from slow to gradual upper rpm range for any distance? Another thing to check is if after "going like stink" and it stalls open the gas filler cap and listen to hear if it has a vaccum in the tank ...from a poorly vented cap. It could be retricted enough to cause that same poor running condition.
Karl
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