who is the goto guy on holleys

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AJ/FormS said:
Well that just reeks of valve lash or very rich
Why are you running the 850? Big power? Hi rpm? Or just cuz?

Wait-a-minute!
The gas sloshes into the carb? That is not supposed to be able to happen; the vent stack goes into the airhorn, some nearly 2 inches higher than the fuel level. I think this is a big clue! You're talking exactly which 850?
Notice the carb shop said it was all good, I bet they ran it on a stationary engine,while you are in a moving vehicle, with the fuel constantly sloshing.
I wonder if that Percy block is not routing the vent properly, or the 850 itself has a defective vent system.

If you take the carb off,plug both vent stacks and the inlet, then you should be able to turn that carb upside down with no loss of fuel. The only way out for the fuel, when upside down is, or should be, thru the stacks.
Well; the main lines and the accelerator circuits might dribble a bit until they are empty.
Each bowl holds about 50cc, and if all or most of it drains, that is a big issue! Find out why!
Click to expand...
the 850 is 4781-3
 
There are only a few reasons the fuel bowls will have that much gas in them. The floats are bad, the fuel pressure is to high/creeping and overcoming the needles and seats or the needles and seats are bad.

Have you verified the fuel/float levels when it start's acting up? If not this is the first thing you need to do.
 
justinp61 said:
There are only a few reasons the fuel bowls will have that much gas in them. The floats are bad, the fuel pressure is to high/creeping and overcoming the needles and seats or the needles and seats are bad.

Have you verified the fuel/float levels when it start's acting up? If not this is the first thing you need to do.
Click to expand...
thanks i will do that...it sucks the carb was just in the shop, and was opened up and gone through and tested...:( and was to be spot on...lol
 
Guys!
OP says fuel is sloshing into the throttle-bores.
Open for a recap
>when I took the 850 off I noticed that if I tipped it just a little front to back gas poured into the body of the carb
>stock fuel pump 6 psi.
>pv is blocked off.
>thanks I did want to note that when I first took off the 850, I noticed if I rocked the carb from front to back just a little, gas would pour into the center of the carb...I asked the carb guy he said he noticed that as well he had no idea as to why...and said the carb was set up right including the float levels...
>the carb I am using was used on a blower set up....the carb shop looked inside and ck it all out so I am not sure,also the car is a beast all around until 20 to 30 min into a drive....then sux....the 750 does good;all the time.
Click to expand...

He is not saying it is sloshing over, or out of the vent stacks!
He says Center
There are no factory holes that can allow this to happen.
OP said this was a blower carb,returned to NA. I have no idea what this procedure entails other than that the PV system has to be modded.Ima thinking this has something to do with it.
There is no way fuel should be sloshing down the bores, that is coming from somewhere else than the vents!
Ima thinking somebody drilled a hole which shouldn't be there!and now venturi pressure is getting into the bowls, and/or sucking the fuel out,un-metered.

Now, OP, it's taken us 29 or so posts to get the story thus far,lol. The recap above is from page 1, and many posts.Is there anything else you can tell us?
Go look where that fuel is coming from.Then go look in your 750. Compare the two. Tell us what you find.
 
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AJ/FormS said:
Guys!
OP says fuel is sloshing into the throttle-bores.


He is not saying it is sloshing over, or out of the vent stacks?
There are no factory holes that can allow this to happen.
OP said this was a blower carb,returned to NA. I have no idea what this procedure entails other than that the PV system has to be modded.Ima thinking this has something to do with it.
There is no way fuel should be sloshing down the bores, that is coming from somewhere else than the vents!
Click to expand...
thats what i was thinking as well....thanks to everyone for the input and advice.
 
the carbs i've had that run properly at operating temp are quite grumpy cold and while the motor is warming up. fuel mix is lean as it is warming up.
also, you shouldn't have to open the throttle to warm start if your idle mix is set correctly. sounds like it might be quite rich...
 
Started it today ran like crap..had to turn up the idle up to keep it running..my summitt fuel gauge read 7 to 7.5 un steady.it's a stock 440 mech pump..the floats were set just below the holes..also vapor was coming from the front vent tube...pulled it and rocked it a little back and fourth gas still comes out of the four round things in the center of the carb. put the 750 on ran great....
 
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