Issue with flooding on Weber Carburator

[Gerhard Peters]

I have the Weber Carburator as per this video https://www.youtube.com/watch?v=IN9-ov2P5wI

I have problems with it flooding. I have completely rebuilt it and have done a proper adjustment on the floats.

I'm thinking that I'm missing something but can't figure out what else to look for

 

[Gerhard Peters]

I also already replaced the floats that I bought separately and still the same

 

[jimmbo]

What is it doing to indicate it is Flooding?


Dirt/Foreign matter holding the inlet valve(s) open
Improper Inlet valve(s)
Missing gasket for inlet valve
Improper float adjustment
Improper float
Float too Heavy
Fuel Pressure Too High

 

[achris]

I have the Weber Carburator as per this video https://www.youtube.com/watch?v=IN9-ov2P5wI

I have problems with it flooding. I have completely rebuilt it and have done a proper adjustment on the floats.

I'm thinking that I'm missing something but can't figure out what else to look for

Welcome to the Weber dribbler... It's a standard feature of these carbs, and why I sold my 4.3LX and replaced it with a 4.3MPI...

I had tried, so many times :facepalm: to fix this very problem. I did a pile of bench tests, simulating the dribble, and reproducing it. Every time I spoke to a carb 'specialist' I was told what I was see (with my own 2 eyes!) was impossible...

You have a few options. Replace the carb with an Edlebrock 1409, replace the engine with an MPI, live with it...

The choice, is yours.

Chris....

 

[Rick Stephens]

I have had no problems with the Edelbrock 1409. Nice part is, I believe you can grab a new 1409 and calibrate it using same jets, needles and springs as your Weber. Don't expect the Edelbrock 4.3L calibration kit to do you any good, start where your Weber is or even pull the Weber jets, needles and springs and use them in the Edelbrock..

 

[achris]

I have had no problems with the Edelbrock 1409. Nice part is, I believe you can grab a new 1409 and calibrate it using same jets, needles and springs as your Weber. Don't expect the Edelbrock 4.3L calibration kit to do you any good, start where your Weber is or even pull the Weber jets, needles and springs and use them in the Edelbrock..

Here's the factory jetting for the Weber (and the place to start with the 1409)....

​

 

[Rick Stephens]

Here's the factory jetting for the Weber (and the place to start with the 1409)....

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I found the Edelbrock 4.3L calibration kit... I want to say it was #1485, but that is by memory, is uselessly lean for a Vortec 4.3L engine. Seems everyone else did as well. If the OP decides to go that route I am happy to share the results that several of us compiled as we duplicated each other's efforts calibrating new 1409s. Hint, we all ended up very close to the same if not identical parts.

 

[achris]

... is uselessly lean for a Vortec 4.3L engine. ....

Despite not telling us in this thread.. :facepalm: I dug a bit and found out the engine's not vortec...

Chris......

 

[alldodge]

I have the Weber Carburator as per this video https://www.youtube.com/watch?v=IN9-ov2P5wI

I have problems with it flooding. I have completely rebuilt it and have done a proper adjustment on the floats.

I'm thinking that I'm missing something but can't figure out what else to look for

Its either not adjusted correctly, or as jimmbo mentioned there is something keeping the needle valve from shutting off fuel. Slim but may also have to much fuel pressure.

I have no issues with my Weber

 

[Gerhard Peters]

Here's the factory jetting for the Weber (and the place to start with the 1409)....
​

achris The image with the calibration you posted does not show for me. Can you send that to me in a private message or repost it here?

I just purchased the Edelbrock 1409 on Amazon. Btw from the outside, the Edelbrock 1409 looks very similar to the weber. It has the accelerator pump in the same place ect..

Also, what do I do with the electric choke? Mine currently has the vacumn choke which I already disconnected. Second how about all the vacumn ports (or whatever they are called)? Do I plug them up?

 

[Bondo]

I just purchased the Edelbrock 1409 on Amazon. Btw from the outside, the Edelbrock 1409 looks very similar to the weber. It has the accelerator pump in the same place ect..

Ayuh,..... Because it's the exact same carb made from the exact same parts, 'n pieces,.....

 

[achris]

Also, what do I do with the electric choke? Mine currently has the vacumn choke which I already disconnected. Second how about all the vacumn ports (or whatever they are called)? Do I plug them up?

Find a 12 volt source and hook it up. Usually the coil + terminal is good enough. You want a purple wire, as that's 'switched'....

I'm currently in an airport and don't have access to my usual resources. I may be able to send it to you in about 16 hours or so...

I have no issues with my Weber

It was only the 9600 and 9666 carbs that had the problem. I believe yours is a 9750..

Chris.......

 

[Gerhard Peters]

I got the new carburetor and I'm now thinking that it is not it after all. I installed the new carburetor and started the engine and ran fine pretty much right away (after a bit of timing adjustment). I stopped the engine to add some more fuel to the tank and turned the ignition on and the fuel pump started running right away. It took a few seconds and the carburetor started to flood just like the old one. Now my engine intake is full of fuel again

Maybe I should have checked the fuel pump first. Any ideas?

What is the best way to get rid of the fuel in the intake? Whichever intake value is open for a cylinder it will be full of fuel.

 

[Gerhard Peters]

What exactly is the fuel pump suppose to do? Does it auto-shutoff once it reaches a certain PSI?

Last week when I flooded the engine I took all spark plugs out and then turned the engine for a bit. Probably will have to do that again

 

[Gerhard Peters]

Another thing did I possibly damage the new carburetor floats with the over flooding? I hope not

 

[jimmbo]

I'm going to go out on a Limb here, Is the Fuel Pump the stock Pump?

I have never heard of Floats being damaged by flooding.

How long have you owned this boat?

 

[Gerhard Peters]

Yes, it is the stock fuel pump. This is what I got https://www.amazon.ca/gp/product/B0027I88XE/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

I bought the boat two months ago for really cheap with a nonusable engine. The engine was not winterized.

I bought a used engine.

 

[Gerhard Peters]

Since the boat has been sitting for a few years I figured that buying a new carburetor made sense. Maybe I should have spend more time testing

 

[Lou C]

And just how is the electric fuel pump wired up? Because if its energized when the ignition is on, but the engine off that is WRONG and DANGEROUS. There needs to be a circuit via oil pressure switch to cut power to the pump when the engine is not running or stalls. Or else you have dangerous flooding. Why I prefer mechanical pumps on carbed engines!

 

[Gerhard Peters]

The electric fuel is properly wired the way it came from the factory. The starter will energize it on the initial start and then the circuit from the oil pressure switch takes over. I have tested that setup and everything seems to be working

My question is does the fuel pump run at all times or does it cut out once the floats close?

Back in the days, I used to work as a car machine (80's). Everything was mechanical back then when I worked on 70' cars and trucks. I wish that was the case here too