Download a manual from the web and read the detailed instructions - they are the two weird units with the red screws that sit on the top of the crancase and they adjust the height of the exhaust port openings as you increase the revs.
When cleaning them, start from the pressure pipe at the crancase and clean the check valve (small white unit where the pipe joins the lower crankcase) and check that it only operates one way, then clean the pipes up to the solenoid and the solenoid itself - I use regular carb cleaner with it's thin pipe attached. Then clean the Y pipes from the solenoid to the valves. All joints should be tight and ziplocked so remake as needed.
Then clean the RAVE valves themselves - flip the top off and check the diaphragm - any deterioration and they need replacing (kits are available). Pull the units off the crankcase and clean thoroughly and make sure that they operate smoothly in their bores.
Using an inferior oil can cause them to clog up and stick so stay with a good synthetic. I have had good results from Amsoil Injector Oil but if you can get Seadoo's XPS then definitely stick with that.
