Holley secondary flooding

[William F.]

I have an ongoing problem with flooding from secondaries on my Holley 3367 after repeatedly adjusting floats with the proper procedure. I know how to do the procedure-have had similar carb on other cars for years without adjustment problem,but on this one, level will look fine after adjustment, then I drive it and experience flooding from secondaries only. When I remove sight plug, fuel pours out. When adjusting, very little turning of the adjustment nut makes level either too high or too low. I've changed needle to no avail.This is an almost new carb. Haven't checked for excess fuel pressure, but if too high a pressure is present, wouldn't primary as well as secondary flood? Could the secondary float be hanging on something?What? and how to correct?You'll see my car is a '67 and know they came with non adjustable 3810, but I bought the 3367 since it does have externally adjustable floats.
Thanks in advance.If need be please also e-mail me advice.

[Edward J.]

Re: Holley secondary flooding

Bill, it may be possible you have a heavy float or something causing the float to hang up when it drops there is a adjustment for the drop of the float, since theres a new needle and seat it really doesn't leave much.

[Clem Z.]

Re: Holley secondary flooding

side hung floats ? make sure the float pivot shaft in the float bowl is not loose or moved allowing the float to move towards the metering body and hanging up. take of the bowl turn it upside down and apply about 10#of air pressure to the fuel inlet and use a soap solution around where the needle/seat comes into the float bowl. here is what i use to pressurize the float bowl

[Dale S.]

Re: Holley secondary flooding

I had that problem, swapped parts between 2 carbs and final got it when I changed the metering block gasket, The kit had the wrong gasket in it, as the problem moved from one carb to the other with just the change of that one gasket. Dale

[Norris W.]

Re: Holley secondary flooding

I just saw this on one of the carbs on a friend's tri power. It turns out the threads in the top of the float bowl where the needle/seat screws in were stripped and not holding position.

[Gerard F.]

Re: Holley secondary flooding

Bill,

As Clem says, if the float is loose fore and aft in its pivot shaft, the float will move forward (with braking) and hang up on the metering plate.

I had the same problem with the secondary float on a 3810 for this reason. I pulled the bowl and bent the float back toward the back of the bowl (just slightly) with my thumb, checked the pivots, and the problem went away. If you take a close look at the position of the float fore and aft, you'll see that there is not much clearance to the metering plate. Don't bend it back too far or it will hang on the back of the bowl.

Could also be the needle and seat, or too much fuel pressure, but bending the float is worth a try.

See the 4th post down in the Similar Threads. Looks like the same problem as yours.

[Jim T.]

Re: Holley secondary flooding

William I had a problem with a Holley's front float. This Holley came with plastic floats. The front float developed a leak and took on fuel inside the float. Changed to Holley's metal floats.

[William F.]

Re: Holley secondary flooding

Thanks to all for suggestions,but, IF float has some back and forth movement on its shaft, how do you get rid of this "slopThanks again in advance.
'67 C60 L79 marina blue/bright blue Coupe

'67 Roadster

'

[Fred Y.]

Re: Holley secondary flooding

William , it may be as easy as the other gentleman suggested about gently bending the bowl forward to stop any interference. Or possibly , finding some piece of fuel resistant material in your workshop to slide over the shaft & reduce the slop. Hobby shops sell all types of small & micro size brass tubing you could use & cut off with your dremmel & them secure on the pivot shaft.
Don't give up !

[Clem Z.]

Re: Holley secondary flooding

Thanks to all for suggestions,but, IF float has some back and forth movement on its shaft, how do you get rid of this "slopThanks again in advance.
'67 C60 L79 marina blue/bright blue Coupe

'67 Roadster '

tap the shaft back into the float bowl with a hammer. first make sure the shaft is not loose in the float bowl. if it is loose and can be removed it and use a hammer to flatten the area that presses in to the float bowl

[William F.]

Re: Holley secondary flooding

Clem,
Flatten hole where shaft inserts or end of shaft that inserts into hole?
Thanks

[Clem Z.]

Re: Holley secondary flooding

Clem,
Flatten hole where shaft inserts or end of shaft that inserts into hole?
Thanks

just flatten the shaft where it goes into the hole in the float bowl a small amount and tap it back into the float bowl. do this if it is loose enought to remove but if it is tight in the float bowl just make sure it is tapped all the way into the float bowl.

[Clem Z.]

Re: Holley secondary flooding

if the pin is OK and the float still has a lot of forward and backward movement just spread the ear on the float where the pin goes thru to take out the movement. do the one facing the center of the carb.

[William F.]

Re: Holley secondary flooding

Checked my fuel pressure today-it was 7-8 psi at 2000rpm. Book calls for 4-6.5. Is this higher pressure overcoming my secondary needle/seat and causing my secondary only flooding and inability to keep fuel at proper level at sight plug? Check was made with my 25 year old Sears & Rearback vacuum/fuel pressure gauge, but seems to work OK. Should reading have been made at just idle rpm or was the 2000 rpm used for measurement OK?Help appreciated since I'm loosing sleep over the problem!

[Clem Z.]

Re: Holley secondary flooding

Checked my fuel pressure today-it was 7-8 psi at 2000rpm. Book calls for 4-6.5. Is this higher pressure overcoming my secondary needle/seat and causing my secondary only flooding and inability to keep fuel at proper level at sight plug? Check was made with my 25 year old Sears & Rearback vacuum/fuel pressure gauge, but seems to work OK. Should reading have been made at just idle rpm or was the 2000 rpm used for measurement OK?Help appreciated since I'm loosing sleep over the problem!

what is the hole size in the needle seat ?? the larger the diameter the harder it is to control the higher pressure. this is why i tell people who are not racing their corvettes to use the .097 diameter one vs the .120 diameter one