Who uses a Flow Control valve...

crammit442

makin' legs
Location
here
2lick said:
Any dangers in using them...


No. Set it where it opens before it allows the stinger hose to get overly hot. If you're not sure, call Jetworks for exact setup. How you plumb it and adjust it makes a big difference.

Charles
 

Frosty

New York Crew
Location
Western New York
I've never used a flow control valver persay... I have installed a mikuni main jet in the cooling line at the stinger... that seams to work pretty good... just don't go too small on the jet size.
 
It made a big difference on a Riva Red pipe for me. I'm running a B pipe now and have never tried it w/ out the valve. In theory it seems like a good idea to me...
 

Takeastand SJ

R.I.P. 8/9/2008
Location
Washington
I use on on my B pipe, some say they don't work on b pipes because they like back pressure but it makes more sense to me to have a dry box for better low end.
 
im running one with a bpipe. water box stays dry at idle which means its dry when you hammer the throttle. i had a restictor previous to the valve and while it was better than unregulated flow, it still aloowed the box to get SOME water in it at ilde and not enough at high rpms. its a good, effective and cheap mod.
 

Mile9c1

X-H2O.com
Location
Grand Rapids, MI
I tried one on a B pipe and it blew, so I trashed it (actually sold it). I don't think "in theory" they work like people think they do. First off, your waterbox never dries out, even if you run the valve. Second, if your motor's running, the waterbox never fills up with water. 3rd, reducing back pressure is ass-backwards to 2-stroke operating theory. Less back pressure means there is less force to return the unburned fuel charge back into the cylinders where it should be when the exhaust ports close. So with less back pressure you're burning less gas, which means less power.

I think if the valve works for you, you might be too rich on your jetting. And having less back pressure means you have a leaner charge left in your cylinder, so it'll burn better, making you think you got rid of a hesitation that was just bad jetting. You're wasting gas and making less power.

I'll stick by this theory until someone posts something that makes better sense (which nobody has done yet). Assuming that back pressure is bad is a very very wrong assumption. The whole point of the water screws is to add backpressure... the top screw adds the most backpressure and you'll find that the top screw gives you the best bottom end. Hmmm, funny how that works :27:

I have no dobut people can get the valve to work for them, but it's completely unnecessary IMHO. Anyone here ride my X-jet at Freestylefest? I ran a crapload of water into my waterbox (I tried many drier settings and decided on the "wettest" one was the best). I had one unrestricted stream going into the chamber stinger and one lesser stream going into the back side of the waterbox (it was a TDR box). TDR boxes are less restrictive than OEM boxes, but I ran about twice as much water into it as you would into an OEM box. And that made the best power, with no hesitation even after prolonged idling.
 

wildman326

Who else?
Location
Kansas
I've always found the FCV to help bottom end . . . I know when the spring goes out you can definately tell . . .

As far as being to rich . . . I'm pretty sure my carbs are set up lean. I've had lean seazures when I go WOT too long.

It was my understanding that back pressure was good for higher speeds and less back pressure for lower speed or bottom end. Something about the length of the return wave.

BTW How does the top screw add the most back pressure?
 

Flash-FX

No Square..No Round..FX-1
First off , Factory pipe uses "water temp" to help control exhaust gas velocity.
The hotter the gas, the faster it can travel. When opening the "top" screw it
allows cold water to enter the "chamber" sooner so it cools (slows) down the
charge, creating so called "back pressure"=More low end.
 

waxhead

wannabe backflipper
Location
gold coast
Flash-FX said:
First off , Factory pipe uses "water temp" to help control exhaust gas velocity.
The hotter the gas, the faster it can travel. When opening the "top" screw it
allows cold water to enter the "chamber" sooner so it cools (slows) down the
charge, creating so called "back pressure"=More low end.

its more about the hotter the pipe the faster the sonic wave and that helps the scavenging in the exhaust system
by closing of the stinger area you get a stronger signal from the converging cone that helps it rev out harder

the screws adjust the temperture of the pipe and there for shape the sonic wave speed
 
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