Engine size and RAVE valves??

[stoltjr]

Ton's of great info on here guys, thanks. I have just purchased two jet ski's, a 97 gtx and a 97 xp. After reading this forum I have already removed my carbeurators and cleaned them and replaced my fuel line and cleaned the fuel system components. I have also learned how to adjust the cable from the carb to the oil pump, the guy that had these before me had no mechanical ability whatsoever. I have done a lot of searching, but have a couple of simple questions.

(1) what size engines are in my ski's? The guy before me didn't know and I'm not sue how to tell, I don't see it marked anywhere on the engine. I need to know so I know how to set the high and low speed fuel mixtures.

(2) I have read that the RAVE valves either need to be threaded all the way in or flush with the black plastic for better take off or for long periods of WOT. Which setting is for which performance?

Thanks a ton guys!

BTW. inside of my fuel lines and filters were horrible, I have no idea how these things even ran! Everything was full of a green gel-like gunk that sticks like glue, can't wait to run them again, should have a lot more power!

 

[stoltjr]

O.K. I have figured out that my engines are 787's so am I correct that the LSA is 1 1/2 and the HSA is 0. This is the info that I have gathered from lots of researching this forum, I would just like someone to verify.

Also, I have found a couple threads on cleaning the RAVE valves, however I am not sure how to adjust. Are they set all the way in for better take off, and flush for extended WOT, or the other way around. Mine are definitely not flush now and I would like to no before I disassemble. THANKS.

 

[derek]

i hear people say set them flush. do a post search for RAVE adjustment. and RAVE cleaning. you will find all the info you will need. tomcat did a nice write-up on them with lots of very good pics.

 

[tomcat&family]

Mine wasn't really a how-to, though, but I did take quite a few pictures. If I get around to it, I will likely make a how-to, since I have another GTX that needs to have the RAVE valves cleaned.

The best info I found for RAVE valve cleaning was found here. I also downloaded the exploded views and did a Google search. I found a snowmobile website that had some pictures to give me an idea of what I was looking at, and that helped immensely.

In the end, cleaning them is pretty simple. Just take your time and be sure not to lose any of the o-rings, springs, etc. I recommend grabbing an empty coffee can for the parts along with some rags for the oily mess that you will likely encounter. The only tool you'll need to get them apart is a 10mm wrench.

As for adjusting them... mine are screwed all the way in on both boats, and I haven't bothered with adjusting them. It almost looks as ifsome sort of special keyed tool is needed to turn the red adjustment cap.

 

[stoltjr]

Thanks for the info guys, I had already found Tomcat's thread while searching around, in fact it is now on my favorites list, great pics and info!
I will clean them tonight and since mine are set all the way in I will probably leave them. Thanks again for the responses.

 

[timmyboy76]

gtx....LSA=1, HSA=mag=0, pto=1/2
xp....LOW=1.75, HSA=0....
...:cheers:

 

[stoltjr]

Excellent, that's the info I needed! Thanks a ton, hope to have her running tomorrow and maybe even a test ride!:hurray:

 

[seadoosnipe]

Raves?.....

Here, you may find this thread of good use. It has a break down of internal parts of the 787cc Rotax, including the RAVE's.

In adjusting them, they were originally set all the way in. Then, Seadoo put out a supplemental guide saying to operate them with the red caps flush to the black ring of the cap. I've found that mine perform best, all the way in. Some have pointed out, by changing the spring tension on the guillotine valve higher, it builds lower end torque quicker before the spring tension is overcome by the pressure of the exhaust gases.

http://www.seadooforum.com/showthread.php?t=3554

 

[stoltjr]

Thanks for the great link Snipe, I am an auto tech and am very interested in learning the inner workings of these PWC's. Turning a wrench is easy, understanding how everything works takes a bit more research! THANKS AGAIN!!

BTW, I took the GTX out for a test run this weekend after rebuilding the carbs, replacing the fuel lines, and cleaning the filters and fuel switch. Ran great! Thanks for all the great help.:cheers:

 

[Innkeeper]

When I cleaned mine, they were adjusted all the way in. I decided to adjust them flush, out when I did my test run. Low end was horrible until I hit 4000rpm, the it took off. I adjusted them in and the ski took off great.