How to service Rave Valve---Pictorial---

[Rampage]

OK I know there is a million threads on how to do this...but I was bored. I see alto of people still nervous on servicing these even after reading on how to do them. (even I was)....but after I did them, I thought to myself that was way easier then I thought it would be....So I thought I would put up some pics on how to do them so people can see just how easy it is.
This is pretty messy so I would def recommend using some latex gloves....took me forever to get it off my hands. I'm sure there is several ways to do this, but this is how I did it. If I missed something please chime in


Start by removing the clip that holds on the cap

Pull the cap off but be sure not to loose the spring under it

Now unscrew the piece under the cap...you may need a 10mm socket to loosen it

Now take a #5 hex to take the 2 screws out

Remove the base....if the whole valve comes out with it just pull them apart after you get it out

Now slide the valve out

Now clean the valve with a wire wheel...and I used some brake clean too

Should look about like this when done

I put a new gasket on as well

Now just reinstall everything and your done

 

[djredman99]

Good job....pics make instructions much better

 

[Rampage]

Yeah its not really the best write up but I hope it will help someone....On a side note, it's very very important to put the Valve back in facing the right direction....mine is stamped TOP on one side, and that it the side that should be facing the pistons.

 

[RFoster130]

Nice write up. Thanks for the pics!!! :cheers:

 

[FritoB]

Nice pictures. I cleaned mine this summer and it is easy. Since I don't have a grinder, I used a stainless steel kitchen scrubber (not steel wool) that was effective in removing the build up. While it's apart, check the small o-ring and replace them if they are brittle.

 

[rau_d1]

Hey Rampage, I did mine a few days ago after 4 years of neglect, I change O'rings and gasket and a good clean, how often do you recommend cleaning. Also, they were black as yours and had some oil on them, is the oil normal?
Thanks :thumbsup:

 

[Rampage]

I do mine every couple of months..might be to much but I am really anal about the up keep on my ski. Yeah being oily and black is normal from what I've seen.

 

[dooser]

Quick question. Other than regular maintenance why do they need to be cleaned? When they are dirty will the engine run poor? Also, (this might be a dumb question) what do the rave valves even do? Thanks

 

[rau_d1]

Rampage, Thanks for your reply !

 

[seadoosnipe]

Quick question. Other than regular maintenance why do they need to be cleaned? When they are dirty will the engine run poor? Also, (this might be a dumb question) what do the rave valves even do? Thanks

RAVE is acronym for "rotax automatic variable exhaust". It is patented and is why the 787cc is capable of making 110hp, for such a small engine. In the days I built high performance 327 and 350 cu.in. motors, all my friends would brag about how they just bought a 650 or 850 cfm Holly carb and was going to beat me come Friday's race. I had a simple 4 barrel quadra-jet at the time. No frills, no big money. But, I did remove my 1:98 heads and went to the 2:02 heads. This gave me a larger exhaust port. The theory is, if you want to burn more fuel, you have to be able to exhaust that fuel. No matter how much fuel you dump in an engine, if you can't exhaust the expanding gases, then your not making anymore power.

The RAVE design is set up so that when you increase throttle, building rpm and horsepower, the exhaust pressure increases through the internal porting of the RAVE housing pushing up agains't the spring tension of the bellows, overcoming it and opening the slide valve. As the slide valve opens, it makes the porting large enough to exhaust more gases. This is where you get the extra rpm and horsepower.

The reason we clean them is simple. The 2 stroke motor mixes oil for lubrication of the roller bearings in the crank, wrist pins and main bearings. Most all the fuel is burned off in combustion. The oil we use is a low ash, which means it does have some carbon exhausted. The slide valve is the first moving part that comes in contact with that carbon (soot). It will build and gum up the slides for your guillotine valve, causing it to stick as it's trying to open. If you've ever been on the water and when going to WOT, there is a hesitation between 4 and 6K rpm, that's usually due to a sticking RAVE. If it's bad and your on the water, you can back off your red caps a few turns. This will alleviate the sticking, but don't use that as a reason not to clean them.

I would like to make one quick statement. The RAVE guillotine valve is easily cleaned with brake/carb spray cleaner and a piece of wood stick. I know everyone has their different ways of doing things, but whenever you use a piece of metal to clean another piece of metal, always make sure the metal you are using to clean with, is of a softer type. For instance, the RAVE slide valve is made of aluminum. Use copper or brass to as your wire wheel. Don't use a Stainless wire. You will not only be removing the carbon build up, you'll be removing the aluminum metal of the slide and in a few years, it won't fit the grooves anymore.

 

[tony8a]

very good info!!!
thanks!
i was reading about rave valves and i found it accidently...

 

[dooser]

Thanks for that info Snipe. This is good to know for future reference. I will be cleaning mine come this season. Thanks again!!:thumbsup:

 

[seadoosnipe]

Your welcome Dooser, but thanks to Rampage for such a good write up, along with some great pix!!!!

For a novice, I think people look at them, without much understanding of them and have a certain amount of trepidation about tearing them down for cleaning. For someone who isn't a real experienced mechanic, this is one of the easiest forms of maintenance that should be done, that anyone with a few tools can do.

In a lot of situations, there are people who have a problem with oil leaking into the bellows, or out around the RAVE, even melted caps. If you are having this problem, then you likely have a leak somewhere. If the RAVE is sealed, no leaks around the bellows, the air inside is stagnant and really doesn't get all that hot. The most common way for hot gases and oil to permeate the RAVE cap or bellows is from where the bellows connects to the bottom of the RAVE housing. In most cases, it is attached by a small tie wrap. Then, the excess is cut off. I've seen the knuckle of this tie wrap cut into the rubber of the bellows, allowing hot gas and oil to pass through.

The best way to keep this from happening is to use the smallest possible tie wrap you can get, then, before attaching it to the bellows and body of the rave, smooth off the top corner piece. This will keep from putting pressure on the bottom side of the bellows.

 

[BMANN06]

Great post thanks rampage! Thanks snipe for the idea of tie wraps too, last time i was in there cleaning these I noticed the steel retaining rings are getting weaker and weaker every time I pull these apart!

Good call on the sticky too!!

 

[seadoosnipe]

You gotta have the spring for the top cap of the bellows but where the bellows connects to the base housing of the RAVE, I use the little tie wraps. They fit the groove well and I've never had a problem with them; except one time I used one that was too big and it caused a hole to be rubbed in the rubber. That's when I came up with the idea of knocking off that top piece of the knuckle of the tie wrap.

At my "Advanced" auto parts store, they have a table with a bunch of low cost stuff on it. The tie wraps are in a round container with a lot of different size and colors, all for $5 bucks.......

 

[Ninetok]

I have used the spark plug hole O-rings they fit the bottom of the bellows perfect and no more leaks.

 

[davistek]

Great write up! I am going to get mine cleaned up and hope that it solves some issues that I am having.

 

[pmartell12]

thanks for the write up, it helped build my confidence enough to try to clean them, and it's a good thing because I found the previous owner lost one of the springs that holds on the rubber boot... all better now

 

[Rampage]

Just wanted to add a side note on this. If you use a high grade oil in your ski, you will not have to service these as often.

 

[scorpio67]

Hello, new here so not sure about proper procedure, but i have a question about the rave valves. I cleaned mine on a 96 xp i just bought. I was wondering if the valves should fall on its own if you lift it up a little?? Mine are really clean now, they were seriously gooed up, but when i slightly lift up on the bellows and valve it does not fall back down. Is that normal?? Thanks a lot, this forum is an awesome resource!!

 

[bigJake]

Hello, new here so not sure about proper procedure, but i have a question about the rave valves. I cleaned mine on a 96 xp i just bought. I was wondering if the valves should fall on its own if you lift it up a little?? Mine are really clean now, they were seriously gooed up, but when i slightly lift up on the bellows and valve it does not fall back down. Is that normal?? Thanks a lot, this forum is an awesome resource!!

they should move up and down freely. sounds like the slots the raves fit into are gummed up too and need cleaned out

 

[scorpio67]

they should move up and down freely. sounds like the slots the raves fit into are gummed up too and need cleaned out

Thanks for the reply! Just to verify, mine move up and down just fine, but i have to actually push it back down myself, are you saying that it should close or fall on it's own when i let go of it?? Thanks again.

 

[bigJake]

Thanks for the reply! Just to verify, mine move up and down just fine, but i have to actually push it back down myself, are you saying that it should close or fall on it's own when i let go of it?? Thanks again.

hmm, I usually just put them in and and move the bellows up and down a couple times to make sure they are moving freely but never really paid attention to if it closes by itself. I assume but have to run outside and check. Gimme 5 minutes. But in the meantime are you 1000% positive you put the valves in facing the proper direction? If they are facing the wrong way, you are going to have broken valves and piston damage.

 

[bigJake]

Thanks for the reply! Just to verify, mine move up and down just fine, but i have to actually push it back down myself, are you saying that it should close or fall on it's own when i let go of it?? Thanks again.

ok, went out and ckecked. Mine don't close by themselves either. During operation, it is the spring inside the cap that holds the valve closed, as the pressue of the exhaust increases it overcomes the tension of the spring and opens the valve.

 

[scorpio67]

ok, went out and ckecked. Mine don't close by themselves either. During operation, it is the spring inside the cap that holds the valve closed, as the pressue of the exhaust increases it overcomes the tension of the spring and opens the valve.

Hey thanks a lot for taking the time to go and check on your machine, that is exactly what i needed to know!! That makes sense now that you say it!!