Hello out there:waving:
I have recently installed a new Barry Grant Road Demon Jr. and would like to adjust the float levels. But I am totally confused as to how this works. I realize that if I turn the adjustment nut either counter clockwise or clockwise that I will put the float at different levels. The question I have is how does the lock screw lock down anything? With the lock screw tight in the adjustment nut the nut still can be turned. I am used to having a lock nut on a screw. Turn the screw and lock it down with the nut. But this is different and I must be missing something.

Any input would be appreciated.
Larry at PapasNova

The nut is the lock and the screw is the adjuster. Hope this helps.

The lock screw and nut must be turned at the same time for adjustment.On a Holley ,clockwise lowers and counterclockwise raises. I believe the Demons are the same.Adjustment is correct when the fuel just starts to wet the threads of the hole .

But on all Barry Grants they have clear sight plugs (a $5 dollar option from Mr Gasket) that keeps the fuel in the bowls. You should be able to see it through the sight plug. By the way unless you have removed and replaced the Needle and seat it was properly set at the factory. Any "extra" fuel you are observing is probably due to too much fuel pressure (5 psi normal to 7psi max) to the carb.

Big Dave

The screw locks the adjuster in place.

Turning the nut adjusts the float level.

Turning the nut clockwise will lower the level, turning it counter clockwise will raise the level.

Remember the engine must be running to properly adjust the float levels, otherwise there is no place for the fuel to go.

Make the adjustment on level ground, not a sloping driveway.

The fuel level should be at the bottom of the sight plug.
Note that if you lower the float, it will displace some fuel and give you a false reading unless you lower the float and then raise it back up or give it time to stabilize the fuel level.
The adjustment works just like a Holley.

Actually since the Road Demon Jr. has a large glass site window you'll want to be about 1/4 of the window with the engine running, and the car on level ground.

Hello out there:waving:
I have recently installed a new Barry Grant Road Demon Jr. and would like to adjust the float levels. But I am totally confused as to how this works. I realize that if I turn the adjustment nut either counter clockwise or clockwise that I will put the float at different levels. The question I have is how does the lock screw lock down anything? With the lock screw tight in the adjustment nut the nut still can be turned. I am used to having a lock nut on a screw. Turn the screw and lock it down with the nut. But this is different and I must be missing something.

Any input would be appreciated.
Larry at PapasNova

To answer your question look at this pic of a needle and seat.

http://www.speedwaymotors.com/eccStoreFront/product_images/400/427-6504_L.jpg

Notice how the nut threads onto one end. It allows the assembly to be raised up or down in the top of the bowl depending on how far the nut is threaded onto the assembly because the nut is the stop. Then the screw goes in the end and sandwiches against the nut to lock the adjustment. You should not be able to turn the nut if the screw is tight because the nut is sandwiched between the screw head and the bowl.

nobody above mentioned fuel pressure - set fuel pressure first before setting the floats because the float setting is dependent on it. Also, the fuel curve will be wrong if you do not run the recommended pressure - usually 7 to 7.5psi.

THEN set the floats.

About the clear sight plugs - depending on the fuel you use they get really unclear after a while so get some old school brass screw in plugs for the bowl and only swap in the clear ones for adjusting the floats. Then swap them back again so the plastic doesn't get hazy.

Not everyone runs a fuel pressure regulator. What kind of pressure are you getting from a stock fuel pump? 6 or 7 psi? Holley sells a 170 gph mech pump that outputs 7.5 psi... No need for a regulator or to adjust fuel pressure with one of those...

nobody take any offense here but the demons are second rate carbs - inconsistent and mass produced - but if you bought a pro systems they are very clear that you need 7.5 psi fuel pressure at the carb or the fuel curve will not be correct. I'm sure if you are 6 or 7 you are "fine" but 4 or 5 doesn't cut it and you will have fat and lean spots in the fuel curve that can't be tuned out.

Lump makes a good point about fuel pressure. It is common for stock pumps to have pressure outside of the range where they were designed to run, so it is always a good idea to double check the pressure (even on non regulated systems). As far as his comments about the sight glasses, we do not use plastic as some carburetor modifiers do, we've been using glass windows a decade now without any issues. Many other manufactures are actually following suite and using glass windows now. More of the problem with the small plastic sight windows is that they can be convex on the back side giving the user a false reading.