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OT. Need answers on 96 Seadoo XP. Rave valve Login/Join 
I recently put in a used valve in the mag cylinder of the 800 XP. The old rave valve was melted. When this happened the first time the factory pipe was hot too and the rubber coupler from the pipe to the stinger had a hole in it.

Question, The new (used) rave valve melted in the mag cylinder but the other one is ok. The Factory Pipe is much cooler than last time. Water is running out of the pisser.

Could it be a clog in the water jacket in the head? What else could be causing this? I thought the O-ring on the rave valve might be the problem but I checked it b4 I put it in today. The ski ran better than it has in a long time. Throttle response is geat. Idle fine. I had to adjust the idle and the low speed screws AFTER the first rave meltdown. I dont think this is the problem though.

ALso there is a different type of water connector on the waterbox..not the rave looking pressure regulator but this was in when we bought the ski.

Any help would be appreciated b4 I go out and pull the head and have to buy new head o-rings.


(tired of working on everyone's ski around here..I just wanna ride [Mad]
Posts: 1048 | Location: Myrtle Beach, SC. USA. | Registered: May 09, 2001Report This Post
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Any air leaks on the carb to that cylinder? For what ever reason, that cylinder is running way too hot...most likely high combustion temps.....but could be water cooling probs too, those should be easy to diagnose though...
Posts: 186 | Location: Houston | Registered: May 29, 2002Report This Post
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Believe it or not..I had the same thing happen to my old XP 800 race ski. And it was water related too.

Some tuners would take the the rave valve off the waterbox and put a Mikuni jet set-up instead...no big deal. It did give better top-end.

Make sure all your water passages are clear..Sea Doos have a weird way of water routing in the first place, but when they get corrosion in the passages it is detrimental. When you get your re-build done...make sure you have the correct jetting in your carbs. Then make sure the high speed screws are RICH and then work your way in, when dialing them in. In any case...pull those carbs off and inspect them! Period.

Also..it would be a good idea to replace the o-rings and head sealing rings if worn excessively.

One more thing, make sure that oil hose has oil in it. The engine needs that lubrication in the worst way. Boy those Sea Doos have a lot of things to watch, huh?

If any of this is confusing...Call Bill O Neal at Watercraft Magic, he is a Sea Doo Guru..and will be happy to help you.

Posts: 1994 | Location: Florida | Registered: April 18, 2002Report This Post
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I did check the oil lines to make sure they were in good shape.

The engine seem so to be on the rich side so I don't think it's oil starvation. Plugs look black.

I will open up the head and see how the water jacket looks. I hope I see a nice clog in there so I won't have to pull carbs or do something more drastic.
Posts: 1048 | Location: Myrtle Beach, SC. USA. | Registered: May 09, 2001Report This Post
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The first thing to do would be to put this thing on a flush kit. Another good place to check is the line coming from the rear of the cylinders. It's normally a clear line and can tend to get plugged with sand and any thing else that enters the water jacket. The line normally exits in the exhaust out let. When the unit is on the flush kit you should be able to see water being dumped into the exhaust out let. The other trick to do on the flush kit is reverse the cooling to the head. That means to switch the line to the rear of the head. Like mike just said the water box is probably hard piped with a main jet. It sould probably be an 80 main jet and the front of the pipe sould be some where between an 80-110 main jet depending upon what in take grate you are using, (water pressure created and water routing).
If you can't find it give me a call I'll be happy to help, I have a lot of experience with this set up in many different forms. If you can post some pics it would be easier to help you. If you have any questions I would be happy to help you.
Travis (313)623-8995
Posts: 281 | Location: Taylor, MI 48180 | Registered: January 06, 2001Report This Post
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Thanks Travis, I will reverse the cooling lines tomorrow. I already had the lines off when I was troubleshooting the pipe and wanted to make sure it was routed correctly and it is.
Posts: 1048 | Location: Myrtle Beach, SC. USA. | Registered: May 09, 2001Report This Post
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Okay here's the latest.

Pulled head and cylinders look okay. Mag cylinder has a very small gouge (size of a fingernail). Piston has good wash except the carbon is pretty thick on the surface.

Pulled ALL cooling lines...no blocks.

Then I thought the carbs might be the problem. The rave valve melted at high speed runs. I checked the high speed adjuster and its was frozen. I needed a vice grip to turn it 1/8 either way. That's all I could get out of it.

CARBS? I think the jets are clogged. This could cause the heat? I see some scoring on the cylinder walls and I am thinking lean on high speed runs but plugs look tan.

What do you think?

Posts: 68 | Location: Myrtle Beach, SC | Registered: March 12, 2003Report This Post
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Seadoos have a lot of problems. [Frown]

1.Exhaust gaskets tend to leak at full throttle causing water to spray into mag cly. air intake and also drip all over #1 carb and starter motor.The new gaskets are much better,they are red in color.

2.Make sure to check the small filters in the carbs, rear cly. carb is always plugged the worst.
The filter is plugged from the junk coming out of the fuel lines.All Seadoos from 94 on have TEMPO fuel line (gray in color). This stuff is the worst excuse for fuel line I have ever seen.Polaris is now using this fuel line also.

3. Move ground cable to a better spot ( extra hole in cly. Because water runs on it from the leaking exhaust gasket.

I could go on all day about Seadoo problems but this is a YAMAHA forum. [Smile]
Posts: 298 | Location: Sunny Fla. | Registered: December 05, 2002Report This Post
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