R.A.V.E. adjustment went bad

[99seadoogtxltd]

I made a very minimal rave adjustment. Now the ski is sputtering and doesn't seem to have the power it had before. There is definitely a noticeable sound difference. I didn't turn the red adjusters a whole turn to be honest. What could I have done wrong? I took the cap off. Unscrewed the red cap til flush, then screwed them in exactly to turns. Thats was about where they were to begin with. I'm completely baffled. I have learned if it isn't broke... don't fix it. When I get it back normal, IM DONE trying to tune it.

 

[AdamXP800]

I really doubt the rave adjustment is your issue. The RAVE only affects the power band. Turning them they open later, screw them out they open sooner

 

[99seadoogtxltd]

Thats what I have heard. But I have done nothing else to it. It starts fine, idles fine. its just when i ease on the throttle it doesnt respond as well and it sputters? what if i adjusted one more than the other? what would happen? it still runs 55 mph. i know i should be getting 60 but it never reached 60 from day i bought it/

 

[SabrToothSqrl]

Adjusting the RAVEs won't do anything you've mentioned here.

You've found something else wrong.

 

[99seadoogtxltd]

instead of the deep throaty sound they usually make, its sounds like it gargling. it sounds like there are more exhaust sounds than the slower normal lopes.. thats the best i can explain it. im taking to a nearby pond Wednesday and see if i can figure it out. if it was fuel related, seems i would have had a harder time starting it or trouble with it idling. ill try to take a video wednesday and see if you can here the difference. i havent touched anything else. this thing is so confusing, its honestly not worth the trouble to me. id lots rather have a boat that my whole family can get on.

 

[99seadoogtxltd]

ill try and change out spark plugs and clean the raves and see if that makes a difference, if not, that thing is GONE

 

[99seadoogtxltd]

Ok, once I take the retainer clip back and carefully remove the black cap, a spring is under the cap... the actual valve right there. What happens if I were to turn it? I didn't use tools. Just with my fingers. Something right in here changed everything. Should I carry it to a seadoo dealership to have it looked at?

 

[- BiRkS_]

That black plastic piece is connected to the bellows and a spring clamp holds it on. in order to clean the valve, you need to remove the RAVE housing via the two allen head bolts per valve.

Something does not sound right. If you can get a video of it, maybe we can help. Does it sound like a "Bog" sound? do you still have grey fuel lines?

 

[99seadoogtxltd]

If I turned the actual black valve under the bellows, would that change the timing?

 

[- BiRkS_]

That is only a cap. It should be tight. That is what holds the actual valve into the housing. Nothing will change the timing, unless you have a punctured bellow, or if you change the pre-load on the spring via red nob on cap.

 

[99seadoogtxltd]

Thats exactly what i did. The red knobs I thought were only for the power band. SO WHAT ADJUSTS THE ACTUAL POWERBAND? I was thingking the red caps did that. Thats why I adjusted them!!!!

 

[AdamXP800]

I believe he is talking about the piston. It should be screwed tight onto the metal slide with the bellows attached to it

 

[AdamXP800]

You need to take the Allen bolts out and disassemble the rave so that you understand how it works

 

[- BiRkS_]

And download a shop manual. Why were you trying to adjust the powerband? Only thing you can do is have it kick in slightly sooner, but then you would get a jumpy throttle and poor mid range throttle range.

 

[99seadoogtxltd]

I fall victim to my own stupidity to say the least!!! Like I stated before, I WONT TOUCH ANYTHING ONCE I GET THIS THING BACK RIGHT!!!

 

[Sportster-2001-951C-Stock]

If you reassembled the RAVE valve the same way it came apart and didn't damage something and put all the parts back in the same order, then it should be working fine. You need to look at the exploded view drawings to make sure they're assembled correctly, remove them from the engine and disassemble the and clean all the parts thoroughly, this procedure may seem difficult at first but it's actually rather easy to accomplish and should be done probably at least once each season, I prefer to clean mine during winterization.

There are a couple of ways to confirm the valves are operating properly, I assume you have confirmed the free movement of the blade to the bottom of it's travel, and after reassembling pressurize the air line, etc....

I'm not sure which motor you have, so cannot be too specific concerning detail but a shop manual will walk you through all of your questions.

 

[99seadoogtxltd]

The only reason I was adjusting anything was for pulling my 2 person seadoo tube. It was bogging a lil. all the power seemed to be in the top end. i was trying to get the power band lower so that it would tow better, because you dont tow people at WOT. 25-35 mph is perfect for the kids. ok. there is a red adjustment screw on the top of the actual black cover that is held on by the retainer clip. up under that contraption, there was w black plastic (bellow?) held on by the springs. i just touched that to see if it was dirty and noticed that i could turn the nut on the top of it (which turns the whole (bellow?)) maybe thats where i screwed up. BUT i unscrewed the red adjustment screw all the way out to where it was flush with the black cap that holds it in. then i turned the actual red adjustment screw two turns in. THATS IT!!!!

 

[Sportster-2001-951C-Stock]

Yes, but you didn't mention the spring that's under the black cap, did the spring come flying out and you didn't notice? I've had this happen to me before, the spring took off and rolled under the engine.

Anyway, if yours is the same as mine, that spring holds the rave valse in the down position until the "air" pressure builds enough to push the rave stem up and overcome the spring pressure.

I'm not sure how much adjestment will impact as mine is either on or off as ordained by when the MPEM cycles the "air" solenoid, perhaps yours is dierect without using an MPEM signal like mine does.

That's why I suggested you should consider downloading the service manual, it contains a huge amount of valuable information I was more than happy to have, including a section on how to test, remove, clean and install the raves..

"noticed that i could turn the nut on the top of it (which turns the whole (bellow?))"

Yes, that nut should be tightened but it's plastic on mine so I cannot torque it more than a small amount or it will strip the threads. I put a deep socket on mine and tighten it hand tight, it's tight enough to stay, and the bellows firction should counter it backing off.

Honestly, I don't understand why so many people resist downloading and reading through their service manuals.

 

[99seadoogtxltd]

Yes I downloaded it. And yes the spring is installed. I dropped one under the motor and had to get an extended magnet to retrieve it.

 

[Strizzo]

on ALL 951 skis and the 800 RFIs, you cannot adjust the RAVE valve, they're actuated by a solenoid controlled by the MPEM.

 

[Sportster-2001-951C-Stock]

"Yes I downloaded it. And yes the spring is installed."

Great, so you should have the assembly drawings and instructions, I think.

Now, if that black plastic nut is lose then can you tighten it clockwise by hand (you may need to place a socket on it, I do) until it's tight? Maybe someone before you tightened it too much and stripped the threads that hold the valve blade?

If so, the rave valve blade may have dropped to the bottom of it's pocket and isn't opening on command of the MPEM.

Do they both seem the same, when you take the caps off are they both lose or is just one tight? Only hand tight with a deep socket is enough, IMO. You haven't removed the raves, so how do you know the blade isn't just laying in the bottom of it's pocket and never moves up?

You've got to carry some of the load here in comprehending what's going on.

I recommend first, pressure check the rave bellows. Then, I would recommend you remove them one at a time and completely disassemble and clean them, check the components to make sure it's all assembled correctly and then reinstall them. Once reinstalled, pressure and vacuum check them again and make sure they move up and down like they're supposed to.

That's all there is to them they just move up and down, up to open the exhaust ports once the engine is in it's power band, then down for smooth engine operation at lower engine speeds.

On mine, I can feel the power increase around 5,000RPM's when those rave valves open my boat almost jumps up in speed.

You probably really can't change when they open by much even by turning the caps all the way in(try all the way in once) b/c the MPEM decides when to turn the "air" pressure that opens the raves. About all you can probably do is defeat them and I have doubt's you'd like the result but I haven't tried that myself, no reason to.

It's also possible to change the 951 engine rave to operate independent of the MPEM, but it involves drilling out holes in the bottom of the mounting base and I've never tried that either so cannot comment on what has to be done exactly and how well it does or doesn't work.

I try to keep my boat as close to factory setup as I can, changes tend to have negative consequences if they're not well thought out prior to implementing them.

So, if you're certain you've reassembled and tested your raves and they're working properly, we'll move on to trying to resolve the other potential root causes of the boat not running properly.

 

[99seadoogtxltd]

But you have to understand, it was running perfect other than LOW, low end power. I tightened that nut with my hand. Didnt check the other one. But it seems I done nothing to cause this to start. Would adjsuting the RAVES make the exhaust sound differently?

 

[Strizzo]

But you have to understand, it was running perfect other than LOW, low end power. I tightened that nut with my hand. Didnt check the other one. But it seems I done nothing to cause this to start. Would adjsuting the RAVES make the exhaust sound differently?

if they are now not sealing correctly, yes. it will sound very "ping-ey" like you have an exhaust leak. maybe ride it a bit with the seat off so you can look at see what is going on down there?

 

[99seadoogtxltd]

Ok if this makes sense, probably doesnt. But Before, it had the slow loping sound.. like big exhaust bubbles in the water, now it sounds like a BUNCH of SMALL exhaust bubbles. I know everyone here will give me hell about that but its the only way i can explain it. Im just going to carry it to a dealership and let them listen to it.

 

[Sportster-2001-951C-Stock]

"But it seems I done nothing to cause this to start."

This is quite possible, something else happened by coincidence and it's not related to the raves.

"now it sounds like a BUNCH of SMALL exhaust bubbles."

To me, the sound is somewhat subjective b/c I judge performance by feel mostly. If you hear a different exhaust tone then it could be related to the raves b/c the raves control the size of the exhaust port.

It could also be related to the exhaust box water valve as well, this device tunes your stinger pipe by filling it with water for low engine speed performance and then flowing less water into the stinger (also known as cone pipe?) when exhaust pressure is increased at higher throttle positions.

If your water valve was malfunctioning it too might cause your exhaust to sound differently, but even a fouled spark plug will make the engine sound differently.

Honestly, I'm still unclear on whether you're describing a lack of low end power or high end power or no power at all. Maybe I'm just not listening and comprehending.

Are the spark plugs new, are they properly gaped, is the fuel shut-off valve closed, lots of things could occur independent of making some small change to the raves, I just want you to tell me the raves are operating properly, one could be stuck in the open position for all I know.