Super Jet flow control valve pop off

[JPCharmin]

I'm about to throw on a pro-series flow control valve and was wondering what the pop off pressure should be for a 701 with the usual head/pipe/hooker/msd/flywheel blah blah blah.. how dry are you guys keeping your waterbox?

 

[Matt_E]

As dry as you can without melting your exhaust hoses

 

[Dustin Mustangs]

The guys at Jetworks will tell you to have it open between 2500 and 3000 rpm. You can't equate that to a pressure until you get it there and measure it on your personal cooling system. But yeah, I would agree with Matt, the dryer the better as long as you don't melt anything. Restrict your stinger down to 2mm or so too.

 

[BruceSki]

It depends on how you have your cooling setup too.

I run paralell cooling and have one line to the pipe and one line to the motor.
The pipe side has a ton of water pressure. I barely have my b pipe adjustment screws cracked and the flow control is screwed in very far. With less water pressure in the system you won't need the flow control adjusted as tight.

The way I adjust is by putting the ski against the dock at the boat ramp or strapped to the trailer in the water with the hood off.

Pull the line off the stinger and stick it overboard with the hood off. Rev the motor until you see water come out of the flow control. If it is too early/too late then adjust it accordingly.

Mine opens very late and I run it very dry. That is how the part was designed to work. Just setting it to a certain popoff pressure and bolting it on will NOT work for everyone's setup.

my .02

 

[JPCharmin]

sorry posted at the same time as you Bruce, great info i think thats what i needed! here is my setup

EDIT: i run a type 4 dry pipe and have a cooling line running from the rear piston on the head to the base of the pipe by the manifold. I have another cooling line coming from the front piston on the head to a pisser, the screw at the top of the pipes chamber going to the stinger (where the flow control valve is) and the other screw on the base of the chamber/top of the stinger going to a pisser.. I am not running dual cooling, the line coming through the hull from the pump goes to the manifold..

 

[BruceSki]

The best way is to visually see how much water is coming out at what RPM. You have to do this in the water while keeping the ski stationary.

Maybe I will double check the adjustment on mine in the spring and take a video of this. This question has been asked multiple times and everyone seems to think there is a magic pop-off number.

It doesn't exist for every setup out there. It is dependent on the water pressure throughout your cooling system.

I can't be 100% positive but I dont think my flow control opens until after 3500 RPMS. I need to get a tiny tach to be sure.

 

[JPCharmin]

ok so basically with the line overboard the water should be starting to spray out ROUGHLY about 1/2 throttle, maybe a little less?

 

[BruceSki]

Thats about what I have mine set at. It will only begin to trickle out at that rpm though. It is blasting almost full by the time you get to full throttle.

 

[WaveDemon]

sorry posted at the same time as you Bruce, great info i think thats what i needed! here is my setup

EDIT: i run a type 4 dry pipe and have a cooling line running from the rear piston on the head to the base of the pipe by the manifold. I have another cooling line coming from the front piston on the head to a pisser, the screw at the top of the pipes chamber going to the stinger (where the flow control valve is) and the other screw on the base of the chamber/top of the stinger going to a pisser.. I am not running dual cooling, the line coming through the hull from the pump goes to the manifold..

I was about to start a thread about how to set up cooling on a type 4. thanks for the post

 

[WaveDemon]

I've heard a builder say 3-4 psi pop off is a good place to start with a jetworks valve.

 

[WaveDemon]

who stocks jetworks vavles other than jetworks? I need to order one.

 

[BruceSki]

jetmaniac

 

[Proformance1]

Great info. Art told me 3-4 is a good place to start, and they come set there out of the package. I check mine while tied to the trailer, same as you Bruce I like mine dry.

 

[Tyler Zane]

dont forget a 2mm restrictor between the fcv and the stinger. when it does open, you dont need a huge burst.

 

[aramis]

It seems to me that a restrictor will change the back pressure that the FCV sees, minimizing the pressure differential required to keep it open at higher flow rates (once the tube between fcv and stinger gets full).

Not saying that restrictor is a bad thing, it's just another one of those factors why "set it to X psi" doesn't work for every setup.

 

[Tyler Zane]

It seems to me that a restrictor will change the back pressure that the FCV sees, minimizing the pressure differential required to keep it open at higher flow rates (once the tube between fcv and stinger gets full).

Not saying that restrictor is a bad thing, it's just another one of those factors why "set it to X psi" doesn't work for every setup.

that's a recommendation from the man himself, not me.

 

[WaveDemon]

dont forget a 2mm restrictor between the fcv and the stinger. when it does open, you dont need a huge burst.

is the restrictor a drilled out jet?

 

[JPCharmin]

Can someone explain a little more about the 2mm restrictor? Should they be on the cooling lines coming from the head like Matt_E had posted awhile back or in between the FCV and stinger like WaveDemon says? Why 2mm and not 3 or 4mm?

 

[Tyler Zane]

is the restrictor a drilled out jet?

your choice, some do use a drilled out jet. i use one of my spare restrictors from my kit.

Can someone explain a little more about the 2mm restrictor? Should they be on the cooling lines coming from the head like Dustin had posted awhile back or in between the FCV and stinger like WaveDemon says? Why 2mm and not 3 or 4mm?

i didnt see that Dustin (he mentioned it, you have a lot of names mixed up) had already covered the restrictor. but we are talking about the same thing. between the flow control valve and the stinger.

it just keeps the water consistent after opening, otherwise it would be a big gush of water...? maybe think of it as a jet in a carb... i didnt question Art when he suggested it, i just do as he says and my setup runs really well.

 

[sjetrider]

for the restricter a seat from a mikuni needle and seat set works brilliantly. Fits snug in a 3/8" waterline.