RAVE valve

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RAVE= Rotax Adustable Variable Exhaust

Kind of hard to explain, but Ill give it a shot :)

When you hit the throttle flipper, the harder you hit it, the more the RAVEs will open. They are on the carb, so one for every piston. If they are not working right, then they wont open or close when they should, causing the ski to run bad or most likely not run at all. If yours are not working I would immeadiatly fix them or if you cant then take the ski to the dealer.

Pretty vague description, but thats all I got :hat:
 
RAVE= Rotax Adustable Variable Exhaust

Kind of hard to explain, but Ill give it a shot :)

When you hit the throttle flipper, the harder you hit it, the more the RAVEs will open. They are on the carb, so one for every piston. If they are not working right, then they wont open or close when they should, causing the ski to run bad or most likely not run at all. If yours are not working I would immeadiatly fix them or if you cant then take the ski to the dealer.

Pretty vague description, but thats all I got :hat:
I am prety sure that they are not on the carb and someone well give you a beter description soon I am sure. no offence WebToad216
:cheers:
 
well i think the thing runs ok but i can remember when i got my 96 xp back in the day i thought holy shi% when i hit the gas.....this one is just ok but after it gets going it will run about 52 to 55 on the big end.....i just pulled the pump off and installed a new wear ring but i havent ridden it yet to see if that was the problem...i was wanting to know what some of the problems i need to look for with th RAVE....i dont know anything aboit them....
 
hey nos...you should be say'n....holy S%*/, when you rap that throttle on that ski...check fuel delivery as well, and those geotine slides/raves..should be clean/ed. Any build up of carbon, will potentially cause them to stick. in a sense, they keep the motor in the powerband...:cheers:
 
now i see alittle oil on the back one comming from bottom of the valve.....does it need to be cleaned or rebuilt??
 
Just clean off the carbon. Nothing needs to be replaced unless the rubber parts are ripped, torn, or if your o-ring is crunchy.

The rubber parts are all under the plastic cap, the O-ring is at the top of the valve stem below the aluminum housing.

Be sure all springs look healthy, especially the one that holds the rubber diaphragm to the plastic part that screws onto the top of the valve stem.
 
i sure wished someone on here that know about these things lived close to me ....i guess i will take a look at them sunday after the ride.....hope i dont tear them up...lol how do they mount to the motor?
 
Not much holds them on.....two hex screws each. The one closest to the curve of the exhaust pipe requires a little thinking about disassembling it - like a puzzle.
 
well i pulled the one closest to the center of the unit today.......i got the top off and the spring out but was not sure how to get the center out.....i put a scoket on it and it would turn but i afaid i was going to break something so i put it all back together ......i will wait till i have alittle more time i was rushed today.....bothe red caps were screwed in ....do i need them flush with the cap????
 
That center cap will seem to spin forever before it comes off. It is threaded on to the top of the exhaust valve stem.
 
Here is some information on the RAVE Valve;
The RAVE, (Rotax Adjustable Variable Exhaust) valves are located above the exhaust valve. There are 2 of them per engine. They are round with a red adjustment screw in the middle. It has a clip that holds it together. How they work is that they open the exhaust port larger as the engine rpm's increase. When the rpm's drop down so do the RAVE valves. They work on the principle of the pressure of the exhaust system. Rpm's increase, pressure increases and the valve opens, rpm's drop pressure drops, Valve closes. They should be de-carbonized annual. To disassemble the rave valves, remove the spring clip on top, remove the black cover. There is a spring under the cover. Remove the piston by turning it with a metric socket. On the bottom of the piston is the rubber "Bellows" be careful with the small retaining spring that hold the bellows on the piston. Remove the 2 allen screws that hold the base on the cylinder. Remove the base and gasket. The long valve won't fall in the cylinder just pull it out. There is an o ring under the base, on the shaft of the guillotine valve. Be careful to see how it came apart as it has to go back together that same way again. On the base, notice the notch that it is facing down. Clean all the carbon off the guillotine valve. I use carb cleaner and 400 grit paper. Check the bellows for any small pin holes. If so replace it. If not, reassemble it on the clean guillotine valve, and install it back on the engine the same way it came apart. The guillotine valve only fits one way. The one closest to the exhaust pipe will come off differently then the other one. You will have to remove the allen screws and turn the base so it clears the exhaust pipe. I would do one at a time in case you forget how it goes back together again. This way you can look at the other one and copy it. Do both engines 2 per engine. Take your time and if you have questions give us a shout. We'll be here to help you out.
If the RAVE valves are dirty it will not rev up correctly and could be causing your problem.

The adjustment knob (the red cap) should either be screwed all the way in or flush to the top of the black ring of the cap. This will only affect performance, as far as how it jumps out of the hole or how well it runs for extended periods at WOT.

I hope this helps.

Karl
 
I recenty took apart and cleaned the RAVE valves on one of our 1999 GTX RFI's, and it was easier than I thought it would be. I read the info in the post above and looked at the exploded views, but that didn't do it for me.



The hardest part was getting the bellows and retaining spring back on, but it really wasn't too difficult. All you'll need is a 10mm socket or wrench and a 5mm hex to remove it
 
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$40 for the bellows? That seems like a bit of money for such a small part.

In the upper right corner of the forum, click on the parts link. You can get two bellows for the RAVE valves in the '96 XP for $51.98 shipped. :)
 
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