RAVE valve adjustment ...?

[hauker]

I read somewhere, that you can adjust the RAVE valves ... How?

I loosened the plastic cap screws under the spring slightly, but that didn't do a thing ... any suggestions?

[Murfs66]

Hauker , To my understanding there are 2 sets of rave valve on the ski. One for the bottom end and one for the top end. the head and the exhaust. I believe the exhaust rave controls how much water is dumped into your exhaust and the other controls back pressure. You adjust one set the oposite of the other to achieve the performance your looking for. For instance all the way down on one and all the way up on the other and slowly screw them in the oposite direction after test runs to achieve max performance......anyone else,,,or am I wrong? I think thats just the start of it....

[Murfs66]

Oh ya dont leave them fully up or down at any point just use this as a starting point......

[hauker]

I think I just had a revellation ... I didn't try to adjust the blue plastic screws on top of the dome, but the black screw-in valves with the rubber fitting underneath the spring ... duh.

Guess that wasn't all to smart

[Rudedog]

To my understanding, the rave valves are the ones ON the cylinders on the 800 and 951 models.
By adjusting them way out you will open the valve sooner and allow exhuast flow quicker.
If you adjust them way in, they will open later as the rpm's increase.
I ran my 800 valves out when I moded my xp, allowing the valves to open sooner decrasing the amount of rpm needed to open them.
If I were you, I would work with them in incriments and get the best result for your set up.
Good luck
Rudedog

[TeamShark]

Rudedog is right. Based on others input, I am running is old ski with the valves out. Hey, remember that starting problem once it is hot situation. Under this same forum Waterworxs indicates that it is the rave valve clearance which is off. I have recently changed the needle/seat and have new jets and also increased the spring from a 65 to 95. My new pop off is about 23. I have lost the huge hisitation off the line and have not tried letting it sit for 30 minutes once I run it to see if she cranks over with push of the start button. What do you think about the rave valve clearance he says that is the cure to hard starts.

[Rudedog]

Thats very possible. Try another set and see what happens.
When I think back, I don't think I ever changed them.
Though I did put a rebuild kit in (ie.spring, rubber,and the seals).
L8TR
Rudedog

[TeamShark]

Sorry. I meant to say Rotary Valve Clearance, but now Waterworkx says that he has never heard about this problem in the 800 motor, just in the smaller motors. Anyway, I hope that my new jetting, springs, needle sets works for my hard "hot" starts.

[Grumpy Old Guy]

Rave valves have nothing to do with starting.

[njrealtor55]

intake to rotary valve clearance should be measured with soldier. the proceedure is in the manual. performe with no gasket on the intake manifold & no lockwashers on the intake manifold bolts. the measurement should be 12 thou of an inch +/- 2 thous. I set our 800's to 11 thous of an inch so we have lots of time before excessive wear occurs.

too much space between the rotary valve and the intake manifold will make the ski very hard to start in the water. if the measurement is more than 14 thous of an inch get it milled. don't forget if the milling is more than 3 thous you have to relieve the o-ring cutout as well.

now for rave valves...

if you unscrew the adjusters on the caps the valves on the cyl will open sooner, but the motor will produce less bottom end. if you screw them in more - you will loose top end. we leave our stock boat adjusters flush with the cap. our raceboats run larger valves and make much more HP, so the screws are backed out slightly...

i have heard that screwing in the adjuster on the waterbox valve will give more power, but i have never played with that setting before... we hard jet our raceboats, and i just keep the stocker flush with the cap to avoid melting the cross-over hose.

hope that helped.