im an idiot. Whats wrong with my carb?

original rochester carb on my new 1954 chevy, stock motor.

i rebuilt the carb ( first rebuild of this model ive ever did ) and when i fired it up it ran better than it ever has.... for about 10 seconds and then gas was coming out of the top of the carb. i turned it off and the gas ran all over the place, let it drain and started it again and it did the exact same thing.

i figured the float was stuck but its to late to mess with it anymore tonight so ill mess with it first thing in the mourning.

i know theres alot smarter people on here than me so i figured id ask. am i right with the float prob or is there something else on the carb i should look into?

thanks alot

 

Yup...the float is stuck or you forgot to install the needle.

 

sounds like float is out of adjustment or something is stuck in the needle and seat maybe rubber from a new fuel line or dirt

 

Float, Float needle, Check float level, Trash in float needle because of no filter? Other wise ur on track--those Rochesters are awesome!

 

Ditto on that and all of the above.

 

What ever the cause it's for sure flooding. Time to take it back apart. Use the supplied guage and read the instructions and look at the exploded view picture really well.

 

thanks guys.

 

It could be the float setting was too high. I've had the float valve stick open before and overfill. I've had a small piece of rust dust from inside the fuel line hold the valve open..
I've also bumped the carb when it was off the engine and got the viton tip of the needle stuck in the seat to where the fuel pump wouldn't push it off and it wouldn't get any fuel.
Stock float settings are for stock fuel pressure.
If you changed the fuel pressure you might need to adjust the float different.

Float adjustment is considered set at the point where it closes off the needle&seat fuel valve and the kit usually comes with a guage and instructions to measure off the gasket surface to set the float level.
When in doubt I set the float where it is level or where the fuel fills the float bowl about 3/4 full to the gasket.
If the engine is running too lean you can raise the float to richen the mix. But only until it's so high it spills over

If the floats too low there won't be a high enough head of fuel over the jets. the higher the head, the more fuel that goes through the jet.

 

In my experiance it takes about 8 tries to get it right... I remember reading somewhere stock settings don't mean much for setting the float since we don't use leaded gas anymore and the float is less boyant in unleaded. I could be totally off base but I found trial and error make you good at the Rochester.

 

well there should be a ruler to check the float level hard to get correct sometimes. but may want to check that the fuel pressure isn't too high with the new needle and seat. my .02

 

If you are confident that you got the float level, and float drop set right , then you probably got something in the needle and seat. That can happen as the lines and float bowl are filling the first time, a little rust or dirt can get dislodged. Here is something that has worked for me, take a little piece of rubber or cardboard to protect the rubber fuel line at the inlet of the fuel pump,fold it over the line and pinch it flat with vice grips or pliers if you have a helper. Then fire it up and let it run until the float bowl is almost empty and engine stumbles. Then unclamp it and let the fuel rush in again. Sometimes that will flush whatever is in the seat out. If not then you are going to have to tear it down again.

 

What was the reason for rebuilding it in the first place,was it doing this before rebuild? could be float level,trash in needle seat,you might have a hole in the float,you said it ran ten minutes then started screwing up.it is rare but I have had to replace floats before from carbs sitting a long time.

 

i said it ran 10 seconds before screwing up. the car actually ran before the rebuild but it has sat for 15+ years with ****ty gas in it, aand wasnt running great. When i took it all apart it had loads of dirt and **** in it so it deffenty needed the rebuild.

i think all the posts about are right about a little piece of dirt or something probably getting stuck in the float needle. im heading to work on it now ill keep you guys posted.

 

I'd get one of those cheap plastic inline gas filters or the gl*** body type and temporarily put it in the line from the pump to the carb. The see trough type let you see if there is a bunch of rust particles or other junk in the system.

One word of caution...every time the engine floods the excess fuel runs down into the crank case diluting the oil. If it is a recurring problem like mine, change the oil. I ruined a brand new 396 chasing a dirty fuel system. I was so pissed at the gas tank problem that I thought about where the the excess fuel was going. The diluted oil wiped the cam and ruined the bearings.

If the added fuel filter shows signs of more dirt, drop the tank, clean it and blow out the fuel lines. If it's a one time happening the don't panic you probably haven't hurt anything.

 

Like Tommy said, you probably have crud in the tank and lines and that's hanging up the needle valve. The clear filter should show you what you have in the tank, but be prepared to pull it regardless since its been sitting.

You could use a remote gas can to get the carb sorted out. I used to hang an old lawn mower tank off the firewall to byp*** a questionable tank.

Bob

 

I agree with tommy, raw fuel delutes the oil, and can cause more serious problems. Fix the float level/needle and seat, then change the oil.

 

UPDATE.

had the ****ing float on upside down. took about 4 times taking it on and off before i relized. LOL sometimes you get so worked up looking at little details you miss the obvious ****, oh well i got a pretty good laugh out of it. haha thanks again guys

 

Didn't even know that was possible.

 

Thanks for letting us know what you found. It usually is something simple.

 

the float it exactly the same on each side but theres a little 1/4 inch tab that stops how far up it will go on the top of the float.

im still and idiot , but id bet that it happens alot these types of carbs, since the float fits perfect either upside down or rightside up.

 

HAVE SOMEONE DO IT WHO KNOWS WHAT THEY ARE DOING .
UPSIDE DOWN ? ? ? (.)(.)s

^^^ don't take that up there to personal , i was probably being a smart***. ^^^