Can't Adjust fuel bowl height

Having a problem adjusting the height of the fuel in the bowl.
I set them low and fuel goes all the way to the top. I pulled needle and seats and cleaned them. Everything seems to work correctly. Needle moves freely but when I turn on the fuel pump, the bowl fills and starts dumping some fuel into the carb flooding it out. I turn off the fuel pump and bowls drop and engine runs fine till I turn the pump back on. Then bowls fill up too much and problem happens again. So basically, no matter where I turn the adjusting nut on the carb bowl, the fuel raises up too much.
I lowered the floats all the way down and turned my fuel pressure down to 4psi to make sure that wasn't the problem.

do you have a return fuel line ? If so check its not blocked

Tex

If one of the O-rings on the float valve body is damaged then it will overfill the bowls.
Gus

I'm wondering if the Q16 killed the viton o ring?
The needle moves freely.

I do have a return system. How can this get blocked?

Where are these o rings that you are talking about?
Are you taking needle and seat o ring?

Yeah I have seen these leak before.

Which type of floats are in that carb?
I would check the weights on them to make sure they are not damaged or hurt some way or the other

I guess you just can't get the o ring? Everything else looks fine.

Summit sells a kit or there is a guy on E-bay that sells a pack of 10 O-rings
https://www.summitracing.com/parts/sum-200400?rrec=true
Gus

Check fuel pressure and replace needle and seats

I'm having the same problem. I ordered the o-rings along with some other misc pieces from Allstate Carburetor. Never tried them before, but seem to have good prices.

https://allcarbs.com/

I should have waited. These are better pricing than the Ebay ones.
I paid $11.13 for 10 shipped.
Your guy alllcarbs is $6.23 shipped for 10.
Plus I'm going to have to wait longer too.
I hope my needles are ruined from the Q16 fuel.

any thing going through the system . Fuel line post carb collapsing or breaking up internally . Especially if older and you have changed fuel ?

Tex

This...Verify the gauge is right too. Needle and seats, as stated, I've had the O-rings shrink and not seal. If you screw the thing out and pull it out of the bore there should be a little felt resistance if its snug enough in the bore. Make sure the floats aren't heavy too.

Carb parts are consumables just like almost everything else. I change out my floats every 2-3 years, stainless or titanium needles and seats, Gaskets, pumps, etc. routine maintenance with little costs.

There is no resistance at all o rings definitely look smaller and not plump.
All 4 are bad.
Never seen this happen before. This Q16 stuff is nasty.

the o ring problem is new to me .I figured he just over adjusted it and no more contact with the adj nut.

Isnt going down in the needle and seat lowering the floats?
I'm pretty low now but can still get the adjusting nut on the threaded part of the needle and seat.

I'm pretty sure if you try to go to low it will flood also o-ring goes below machining in bowl.

Pump gas is also not good on this stuff. Have had this occur before. O rings shrink and get hard.

Q is not supposed to be left in the fuel system. Says on the can.

You can buy the o-rings at McMaster-Carr, 3.61 for 100. Part Number 9452K16, Make sure the surface the ring seats on in the bowl doesn't have anything stuck in there or pitted, also make sure your floats are not heavy. A cheap small gram scale will do it, float weight at the link.

https://www.tapatalk.com/groups/racingfuelsystems/holley-float-weights-t31.html

In addition, I use Vaseline on the needle n seats when installing em.......

I chased a problem like that a couple years ago and it turned out that the new foam float I got was molded a little off and it hit the body of the carb inside the float bowl so it would stick open and not shut off. So once I found it I filed the foam a little bit to cure the interference and then sealed the filed spot with clear nail polish and it's worked well ever since.

And how I found it was by removing the needle and seat from the assembled carburetor and then bending a small (~1/8") right angle hook on a paper clip and sticking it into the hole from the removed needle and seat and hooking into the tang on the float arm and gently trying to move the float up and down. When I compared how much the paperclip and float moved when the float bowl was off the carburetor to how much it moved when it was assembled (and hitting internally) it became very apparent that something was wrong there.

So I ordered a 10 pack of o rings off of ebay. Shipped $11.25
Was cheaper from all carbs but I'm ok with it.
I did order 4 new needle and seats from Summit.
The o rings showed up 1st. Lol
So i picked out the old o rings and sure enough they were brittle and just snapped off.
Going to install the needle and seats in a few after lunch and see if the problem is still there.
Hopefully this was the fix. The needles were cleaned and they move freely.

Are your new O rings Viton, neopreme or what are they made of?
Love that Q16, don't we

I believe they are viton.
I'll have to check but I just installed them and they are a nice tight fit.
Adjusted them to where I think they should be and NO MORE FLOODING.

And yes this Q16 is nasty stuff.
And I do drain the bowls after each use.

Putting this on my maintenance schedule.