Teapot flooding

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adg57
Posts: 35
Joined: Mon Jul 11, 2016 6:27 pm

Teapot flooding

Post by adg57 » Thu Jun 13, 2019 11:35 am

Been troubleshooting carb flooding in my 56. Carberator is stock Holley 4000. Can see fuel running into secondaries at idle & have checked most of the items (Power valve, bleed holes. float) typically suggested. Will test the fuel pressure today (stock mechanical pump). Looks like the pressure should be in the 4.5psi range? Any suggestions on best way to check - the fuel lines are all steel & don't have much free play. Is it best to try to check at the carb fuel inlet? Thanks!
1956 312

adg57
Posts: 35
Joined: Mon Jul 11, 2016 6:27 pm

Re: Teapot flooding

Post by adg57 » Thu Jun 13, 2019 7:27 pm

Ok, I'm getting a reading of 6psi with just a couple cranks. Seems like this is a bit high & might be contributing to the flooding problem. Anyone used an inline pressure reducer or other means to lower the fuel inlet pressure? Do I need a new fuel pump?
Thoughts appreciated. Thanks.
Andy
1956 312

T-Bird Bob
Posts: 10
Joined: Fri Aug 10, 2018 11:00 pm

Re: Teapot flooding

Post by T-Bird Bob » Fri Jun 14, 2019 9:52 pm

Hello ADG57,
I have a '55, but the fuel pump is supposed to be the same. Manual states that the pressure should be 4 to 5psi at 900rpm.
That means it will be probably higher at higher speeds.
That said, I am convinced that this pressure is not your problem.

I had a flooding issue also and I tried to adjust the heck out of the float and the needle valve. It would either flood or starve.
I finally replaced it and all was good.
I think older carbs and especially needle valve can't handle the ethanol fuel. The needle on the Teapot (I know your carb is different) has some sort of rubbery tip for sealing. I am pretty sure that this material was aged and not ready for 10% ethanol. (last rebuilt: 1989).

So just get a new needle valve and be done.

I hope that helps.

Bob

T-Bird Bob
Posts: 10
Joined: Fri Aug 10, 2018 11:00 pm

Re: Teapot flooding

Post by T-Bird Bob » Fri Jun 14, 2019 9:55 pm

Just saw you had a teapot - from your name I thought you have a '57 with a holley 4600.

Btw I would be impressed if a fuel pump fails in a way that makes it producing higher pressure... :mrgreen:

Regards,

Bob

adg57
Posts: 35
Joined: Mon Jul 11, 2016 6:27 pm

Re: Teapot flooding

Post by adg57 » Fri Jun 14, 2019 10:51 pm

Thanks Bob. I'm biting the bullet & rebuilding the carb.
Just bumping the starter gave 6psi fuel pressure reading. Agree that too high pressure from the correct fuel pump (I think) is weird.
1956 312

DynoDan’55
Posts: 30
Joined: Sat Feb 24, 2018 3:34 pm

Re: Teapot flooding

Post by DynoDan’55 » Sat Jun 15, 2019 3:31 pm

T-Bird Bob wrote:
Fri Jun 14, 2019 9:52 pm
I think older carbs and especially needle valve can't handle the ethanol fuel. The needle on the Teapot (I know your carb is different) has some sort of rubbery tip for sealing. I am pretty sure that this material was aged and not ready for 10% ethanol. (last rebuilt: 1989).
So just get a new needle valve and be done.
Bob
Don’t know about what kind of rubber they are using now, but in the past ethanol would make he tips gummy/sticky, and the bowl would run dry. NOS (eBay) brass needle/seat parts solved the issue.

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