Entirely new Jet assembly, won't plane

[Funbunion]

My first post. I'm really thankful to have found such an awesome forum! I've been boating my entire life, and last fall bought my first jet boat.

I have a 97 Seadoo Sportster with the single engine, and when I bought it, it refused to plane. The engine runs absolutely perfectly. Touch the ignition and hits on the first spark. When it's cavitating, it pegs the rev limiter too. I replaced the wear ring and foam seal and it still wouldn't plane. I replaced the empeller and if I have my wife walk to the bow it'll plane and run about 38 mph (my phone's gps speed), but refuses to plane easily. I replaced the entire jet pump housing, wear ring again (just in case), foam seal, and it's still doing the exact same thing.

I have no idea what else to try. Help a buddy!

Thank you so much,
~Chris

 

[Bonmotwang]

The nozzle behind the Venturi has a washer you can put in different ways to change the angle of the water shooting out.
Not sure if this will affect the performance.


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[Bonmotwang]

It is the part circled in the screenshot.
It can be put in in 180 degrees.

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[LouDoo]

Hi, and welcome to the SeaDoo forum.

If you think you're problem in still caused from cavitation you might want to look at the carbon seal. A couple of things you can try, try putting one or two cable ties around the bellow, this will form a tighter seal on the carbon seal to the stainless steel ring.

http://fiche.seadoowarehouse.com/se...76&b=14&c=0&d=-PROPULSION-SYSTEM---DRIVESHAFT

Lou

 

[Funbunion]

Lou and bon;

Thanks so very much. I've not had the nozzle apart, and I had no idea how sensitive these units could be. I'll pull it apart and make sure that it is in the correct orientation. So I just pull the upper and lower encapsulating bolts, and check that washer to be as it is in the diagram?

The guy that I bought it from picked up a rock and I would assume removed that nozzle to remove the rock, and just put it back together incorrectly.

Again, I really appreciate you folks helping a long time mechanic, but one that's new to this equipment.

~Chris

 

[Bonmotwang]

Lou and bon;

Thanks so very much. I've not had the nozzle apart, and I had no idea how sensitive these units could be. I'll pull it apart and make sure that it is in the correct orientation. So I just pull the upper and lower encapsulating bolts, and check that washer to be as it is in the diagram?

The guy that I bought it from picked up a rock and I would assume removed that nozzle to remove the rock, and just put it back together incorrectly.

Again, I really appreciate you folks helping a long time mechanic, but one that's new to this equipment.

~Chris

I was checking on my manual, 2001 sportster. I just checked for your model. The bushing is just a round shape. It is #28 in the drawing here. So it is not like my model you can tune the angle, which means it cannot be wrong. Sorry about the confusion.

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[Funbunion]

Hey, no problem man. Still in the same boat as I was when I started. I'm still going to pull that nozzle apart. From your print, it looks like you may be able to put one in upside down or leave it out. Looking at it now, I think that mine is pointing way north. I'll get to the bottom of it and let you know.

 

[Coastiejoe]

As Lou mentioned, take a look at the carbon seal. If it is bad or set up wrong air will come from within the hull and directly into the impeller. So the impellers spins fast bust has minimal performance as it is pushing air, not water.


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[Funbunion]

It's definitely that carbon ring. I finally just had the time to pull that cover off and look at it and there's so much play in it I can't believe that it gets out of the water at all.

Thank you guys again. I don't know that I would have ever found that. Is pulling that drive shaft a big deal? Looks like it's just splined, slip into place, and the assembly is held together with the pump assembly.

~Chris