1999 Seadoo GTX RFI RAVE problem?

[JBeeson]

My 1999 Seadoo GTX RFI (787) has run great all summer. A few weeks ago it would only hit 3200 RPM at full throttle in the water. Take it out of the water and it hits 6000+ RPM no problem. Put it back in the water and it will throttle up to 3200 RPM and hold.

I have pulled the rear RAVE and cleaned it. The sliding valve was coated with thick black oily sludge. I have also pulled the pipes to the RAVEs and cleaned them out. I also pulled the check valve that goes to the crank case and cleaned it - I am not sure if it was stuck when I pulled it (did not check) - but it works fine now. I was also instructed to pull the front RAVE and clean it too. My question is two parts: if the rear RAVE was coated what are the chances the front RAVE is coated? And second (and most important) is that it appears I will need to remove the exhaust manifold in order to get the front RAVE out. Is that a hard task? I have the 1991 Shop Manual and it looks tough to me. Thanks for any ideas or thoughts.

 

[Bills86e]

The valve on the waterbox is a water controller, it puts in more water at low rpms and shuts it off at higher rpms, it will affect performance if not operating properly, usually the wire clip that holds the bottom of the diaghpram rusts up and eats a hole through the diaghpram. making the unit inoperable.
On the rave valves you can take the black plastic cap off and using a hole saw drill a hole in the cap, then with it on the trailer and running you can rev the engine and see if it is opening up or not.Black oily residue leaking around the rave valves usually means time for a rebuild. If the raves are not
opening up you will usually only get around 5000 rpms and your top end speed will be down about 10mph or so. It injects the most water at low speeds to increase bottom end by slowing down the sonic wave in the pipe, if its not injecting water the bottom end will be boggy with no real hit, that is the water regulators whole purpose.
Test the Rectifier
1. Put volt meter on battery with ski not running, then when running. If over 15VDC
Rec is toast. 2. Open grey box and Disconnect the red wire to the rectifier and see if it run great. restart the ski several times to confirm and if everything worked, Rec is bad, This is the Rectifier test. Bills86e

 

[JBeeson]

Front RAVE valve

Bill I am confused. It appears I will need to remove the exhaust manifold in order to get the front RAVE out. Is that a hard task?? I have tried taking the top off the RAVE to try and squeeze it out but it will not come.

Does the rectifier have something to do with the RPM working fine outside the water but RPM limited to 3400 (under load) inside the water? I did replace the rectifier last year though.

 

[Bills86e]

Remove the black caps and load spring from each, then the "mag"/front one, you'll need a 10mm wrench/socket, and turn the bellow, til you unthread it from the "rave valve", then you can lift it out. Hit them with wire brush/wheel, and for the slots on motor, carefully scrape the inside with screwdriver or something to clean the walls off.

The electonics of the ski operate on DC power. The regulator/rectifier changes the
AC power that was created by the magnito. The Electronic Waveform is the difference, so you prbly won't get any more than 1/2 power to the ski. Bill

 

[seadoosnipe]

Rave

Bill I am confused. It appears I will need to remove the exhaust manifold in order to get the front RAVE out. Is that a hard task?? I have tried taking the top off the RAVE to try and squeeze it out but it will not come.

Does the rectifier have something to do with the RPM working fine outside the water but RPM limited to 3400 (under load) inside the water? I did replace the rectifier last year though.

You should not have to remove the exhaust manifold to get to your RAVE valve. After removing the plastic cap, you will see the top of the rave that holds your bellows on with the spring around it. You'll note a black hex head in the middle. You don't normally need to use a socket, though you can, to seperate the bellows from the slide valve. When the slide valve is released, you should be able to take out the two allen head bolts that hold the casing on and remove it. You need to be sure you have backed it off till the slide valve is no longer attached.

No, the rectifier's sole purpose is to convert AC current to DC current. The component part you refer to is a combination rectifier/regulator. The regulator takes the voltage generated by the magneto and maintains it to your electrical system at 14 volts, the rectifier converts it over to DC.

If your limited to 3400 rpm, you propbably have another problem. The boats have a safety on them that if you are in neutral, you can't rev past 3k rpm. I don't think the skis have this safety.:cheers: