rave valve setting

[trail1]

I got a 98 formula z 670 rave valves are turned all the way in it lacks top end.Should they be set near the middle??

[Max Mach]

Screw them out for better top end.But it will not increase the top end that much,it may be a clutching thing.How many miles on it?

[trail1]

it's got 4600 miles on it.....

[Max Mach]

It probably needs a good clutch cleaning.I would also change the springs in the clutches they get weak after a while.After all the sled is 10 years old.

[Lonetrapper]

from factory at sea level they are all the way in....if you go higher altitudes you have to adjust them out...as the air is thinner...not sure on what height you have to adjust at but I'd say probly good from 0-2000 feet

[snowmutt]

Rave valves are for low end to mid-range and do nothing for top end unless stuck closed..or(screwed in tight).
The valve is designed to control gas pressures in the cylinder/pipe for crisp throttle response with-in the powerband also called ..zoomie effect from the pipe(back pressure)

There's not much you can do with them other then making sure they are cleaned.

Clutching and a compression check would be the 1st 2 things to look at for top end, gearing is another place to look.

Id put them back to where they were . Most of the time the adjustments on those are for race and mountain apps.

mutt