Merc 5.7, alpha 1 gen2, Rochester marine 4bbl flood gushing up out of bowl/float vent!?!

[Wateronthebrain]

Ok, jaming a long Friday and then will not start on Monday? So I disassemble carb, clean, reassemble and mount. Completely floods again?

Anybody with any clue please let me know? Thank you in advance!

 

[jimmbo]

Welcome to iboats

Did you set the Float Correctly?
Is the Inlet Seat tightened, and a gasket used? It the Needle of the Float/Inlet Valve in place?
Is the Float free to move so as to be able to Close the Valve?

 

[Wateronthebrain]

Isn't the needle the same as th valve? Yes to everything else...except I'll check float adjustment tomorrow and let you know for sure...it is a brass float not full of fuel, no holes in it etc...

 

[jimmbo]

The Needle is part of the Inlet Valve, the other part is the Seat

 

[Wateronthebrain]

Gotcha! Thanks for quick response...so, I thought of rebuilding again with another new kit and float? Oh yeah, my primary rods have no retainer or retention clip, etc...so I just lowered air horn by hand real carefully...and attached...do you think I'm blowin' it at that point somewhere because after it was re-flooding, if you will, I pushed down the vent tubes to test float and primary rods, they were not moving at that point...

 

[Scott06]

If flooding either needle and seat /float isnt working or fuel pressure is too high. 4-6 psi max

 

[Rick Stephens]

There is a noticeable lack of quality in chinesium carb kits. It is worth the money to get quality kits just for the needle valve. Cheap needle valves tend to not seal properly.

As noted by everyone, float height is critical. Check and recheck.

And as noted, fuel pressure test is indicated here. T the line and stick a vacuum/fuel pressure gauge on it.

 

[Wateronthebrain]

Thank you gentlemen for your responses. I will enact all of the above directions and report back...what do you think about fuel regulators? In addition to the above or even pressure gage and a regulator?

 

[Lou C]

If you want a good kit, and need tech advice (forum):
Cliffs High Performance
Despite some negative opinions on Quadrajets because they were standard equipment on many GM cars and the majority of GM muscle cars there is a ton of information on them out there and if you have a good core & not a thrown together Franken carb they can be made to work great. I “thought” mine was too old to rebuild and made the mistake of trying a brand new Holley 4160 (because both OMC & Volvo used this exact carb on the 4.3s after Rochester quit building carbs. I had no end of trouble with that thing eventually figured out what was wrong with it but before that I pulled it off and rebuilt the QJet with a good kit from Cliffs. Been fine for the past 4 seasons.
With the float, there is a little clip that is just hooked onto the float bracket. Do NOT hook it into one of the holes that may cause it to jam & cause flooding.

 

[Wateronthebrain]

No mine looks great, in fact I rebuilt it 6 months and had it dialed in the end but then this...I hear you about the "holes", gotcha. I will look up the resource listed above. Thanks. More later...

 

[Scott06]

...what do you think about fuel regulators? In addition to the above or even pressure gage and a regulator?

Identify what the issue is first. IF you bought it kit off amazon or other cheap site parts quality is likely suspect

 

[Silvertip]

Rochester 2bbl carbs would spit fuel in the same manner when the check ball at the bottom of the accelerator pump cavity was not seen during rebuild and then not installed. Not all carbs had them though.

 

[Lou C]

notice the clip for the needle valve, bottom of the pic....

 

[Bt Doctur]

check the fuel pump pressure

 

[Wateronthebrain]

Never saw mine...upon first rebuild 6mos ago I just held it down with a thin
Knife blade while attaching the air horn then slipped it out...the boat ran great until last Friday. My guess is that primary metering rods jiggled loose, came out and the rest is history. I mean I don't even have a retainer ring/sleeve on it.

 

[Wateronthebrain]

Yes I will attach a gage...what about a regulator?

 

[Rick Stephens]

Yes I will attach a gage...what about a regulator?

Only attach a regulator once you identify that one is needed. Make sure regulator is marine rated.

 

[jimmbo]

Yours doesn't have a Retainer(green Arrow) on the Primary Power Piston?

 

[Lou C]

The brown plastic piece I think is the retainer…..

 

[jimmbo]

It is