Question on 1998 Seadoo Sportster 1800 Very high RPM with slow acceleration. No power

[mushroom_baby]

Hi, everyone. I have a question on my 1998 Seadoo Sportster 1800. One very bad day it got leaking manifold and flood both engine and also got a wood stick stuck inside the pump housing and damage the blade. I already replace the whole housing with new impeller and new manifold. And right now i have no idea why it got very high RPM when acceleration in very slow speed until it hit 20 mph, then it will jump to 30-50 mph. If i have more people on the boat (like 4-6 people), it barely go up to 20, and need a long time to hit 30-40 max in very high 7000 RPM. Other question is one side of the engine always start in low RPM and when it hit like 20, then the RPM jump from 4000 to 7000 RPM fast. Other side of the engine stay in 4000 RPM. Please help.

Thanks

 

[Dr Honda]

You have bad cavitation.


Look for an air leak into the pumps.... but I'm going to guess that your carbon seals are bad.

 

[Coastiejoe]

Yep yep.

You are feeding it air. Impellers suck when there is air there. Literally,,,

 

[mushroom_baby]

So I need to change the carbon rings?? Thanks

 

[Coastiejoe]

I would do a bit more digging to confirm, but most likely yes.

You can put wire ties on the bellow/boot in front of the seal and synch them a bit. This will put a better seal against the carbon seal. If this solves the issue then you know where the issue is.

 

[mushroom_baby]

When I try synch, the carbon ring can be move around. Is it normal? Thanks

 

[rjcress]

I would do a bit more digging to confirm, but most likely yes.

You can put wire ties on the bellow/boot in front of the seal and synch them a bit. This will put a better seal against the carbon seal. If this solves the issue then you know where the issue is.

Likely is carbon rings, but could also be the bellows themselves, the seal between the bellows & hull, seal between bellows and carbon rings. or the seal on the insert that attaches the bellows to the hull (not likely... but since there was damage...).

 

[Coastiejoe]

Question on 1998 Seadoo Sportster 1800 Very high RPM with slow acceleration. ...

When I try synch, the carbon ring can be move around. Is it normal? Thanks

I have read it should not move without decent effort and I have read there can be a 1/2 inch gap. I would like to get [MENTION=31048]LouDoo[/MENTION] or [MENTION=16022]Dr Honda[/MENTION] views so we get an accurate answer.

 

[speedster98]

I had cavitation issues on my port pump and tried the wire tie test this weekend. Issue fixed, so I will be replacing mine this winter. I can only force my good pump's carbon ring back about 1/8"

 

[mushroom_baby]

Found out the carbon ring need to replace and wear ring got damage. It got fixed and work great now. Thanks everyone.