What do R.A.V.E. Valves do?

[Zeon]

i see on all big motor builds people have the "RAVE Valves" like on the 951 seadoo motors... what exactly do they do. i hate sounding like i know nothing but i NEED to learn all this inside and out..

 

[ChrisGooch]

Im pretty sure they are the same as power valves. They serve to adjust the size of the exhaust port based on the engines rpm. <<or so i believe>>

 

[fst89lx]

Im pretty sure they are the same as power valves. They serve to adjust the size of the exhaust port based on the engines rpm. <<or so i believe>>

^^ This is correct. Also you should take them apart and clean them periodically. I do this on my snowmobile(s) ~ every 700-1000 miles, I don't know how that would equate to hours on a PWC but I would do it at least once per season depending on how much you ride.

 

[Zeon]

so why dont 701s and stuff have these?

 

[SUPERJET-113]

Here's some good reading info:
http://www.x-h2o.com/threads/20433

 

[Zeon]

thanks!!!

 

[john zigler]

the name R.A.V.E is seadoo's name. it stands for Rotax Automatic Variable Exhaust. every manufacture has their own catchy name for it. but they all really do the same thing.

it has already been said. these are a valve that effectivly changes your exhaust port timming. when the vavle is in the "lower" position, you have low port timming, good for bottom end power, and then it raises, opens the port more, for better top end RPM's and hp.

hope this helps. zig

 

[Hilli]

Here ya' go x, you don't really get to see the bottom/inside of the cylinders that have the PV's all that often so this should give ya' an idea of what's goin' on inside(flow!!);

 

[vomitspot]

they r a v e