96 SPX Losing Power on Water

[Rainman001]

So been racking my brain on this one, I think it has to do with a bad impeller. Have a 96 SPX that will completely lose power while on the water only. If i run it on a hose, there's no power loss at all. By power loss I mean it will be going full speed, and then just go back to idle, then back to full speed, then back to idle, about 5-10 seconds between bursts.

I recently had a stud on the top of the tuning pipe break which caused the hull to fill with water, but I can't see this causing this issue? I've tried moving electrical wires around simulating it moving on the water and can't replicate the issue.

Anyone have any suggestions where to start?? (Also, checked, there is no sea-week or anything blocking the intake).

Much appreciated!!

 

[Coastiejoe]

If the engine itself loses RPMs, then it has nothing to do with the impeller or wear ring. It would be engine related, such as fuel or spark issue.

 

[Rainman001]

If the engine itself loses RPMs, then it has nothing to do with the impeller or wear ring. It would be engine related, such as fuel or spark issue.

If it were this wouldn't I also see it when running on the hose, not on the water? This literally only happens while moving across the water.

 

[vogs77]

I have this same issue with my 95spx and there is another post with the same problem, looks like we all need some help from the seadoo experts here!

 

[Coastiejoe]

Running on the hose only means it runs. The load is MUCH heavier when in the water due to the impeller and minimal wear ring clearance. Now, if the RPMs stayed high and you lost performance, then I would agree with you. But if the RPMs drop and you lose performance, it has nothing to do with the impeller or wear ring.

I would suggest doing a compression test just to see where you are. But i bet you have a carb issue more than anything else.

If it were this wouldn't I also see it when running on the hose, not on the water? This literally only happens while moving across the water.

 

[Rainman001]

Running on the hose only means it runs. The load is MUCH heavier when in the water due to the impeller and minimal wear ring clearance. Now, if the RPMs stayed high and you lost performance, then I would agree with you. But if the RPMs drop and you lose performance, it has nothing to do with the impeller or wear ring.

I would suggest doing a compression test just to see where you are. But i bet you have a carb issue more than anything else.

Thanks for this. Compression on each cylinder is over 110, so no issues there. I'll do a carb rebuild and see if I see anything.

 

[Coastiejoe]

What size engine do you have?

If you do a rebuild, use ONLY OEM gaskets as the aftermarket diaphragms are to stiff and the carb will not function properly. Also, replace the needle and seat s and do NOT replace the pop-off spring if it is within specs. Use the springs you have as for some reason, the replacement springs are almost always wrong either by length and or pressure.

Thanks for this. Compression on each cylinder is over 110, so no issues there. I'll do a carb rebuild and see if I see anything.

 

[Rainman001]

I have this same issue with my 95spx and there is another post with the same problem, looks like we all need some help from the seadoo experts here!

Crazy because every time I google search this issue I get squat haha!

 

[Rainman001]

What size engine do you have?

If you do a rebuild, use ONLY OEM gaskets as the aftermarket diaphragms are to stiff and the carb will not function properly. Also, replace the needle and seat s and do NOT replace the pop-off spring if it is within specs. Use the springs you have as for some reason, the replacement springs are almost always wrong either by length and or pressure.

It's the 717 engine. Thanks for the advice! They've been pretty well maintained, but I doubt the Carbs have ever been rebuilt.

 

[vogs77]

I am 657x with everything rebuilt also.

 

[k_24]

Low compression i had same thing with my outboard

 

[Coastiejoe]

At 120 psi it is normally an indicator that it is time for a rebuild. 110 works. It you are at the bottom end of the normal acceptable range for you engine.

Does the ski have Grey Tempo fuel lines?

 

[vogs77]

Make sure you are using a good compression gauge also. Mine has 115 on a cheep gauge so I got a Snap-on gauge and have 135 in one and 140 in the other.

 

[eavega]

I've had cycling/surging problems on an outboard, and it turned out to be weak spark due to a bad spark wire. Replaced the spark plug wires and it went away. Not saying that is your problem, but might be something to check. Easy check would be to trim your spark plug wire, replace the boot, and see if it resolves the problem..

-E