I need carb help

[transplant87]

so im trying to get my dually running right and when i put a holly on it, it got better then really worse and i cant get it to run right. so can someone help me or if you have a spare carb i can try and see if it is my problem.

[Jim]

Not sure I'll be of much help but I do have a couple questions...

Do you know the model of holley on it now? What motor is it? A carb too big or small just won't work right.

But you said it "got better". From when you switched to what you had (was that carb stock/from factory?) how long and what driving conditions was it "better"? Was the vehicle sitting a long time from when it was better to now? Any other motor changes from better to now?

[Java]

all of my carb experience is with Mercury and Johnson outboards, so take my advice for what it's worth... without knowing what symptoms you're having, I used to get about 3 minutes of greatness followed by hesitation and gas smell when I had the floats set just slightly too high and the bowl level never got quite right, but it would take a minute or three for it to start. Is it a new holley or a rebuild? does it maybe need a rebuild? they are not so hard to do, really just fancy little toilets. it's also possible you have an emmissions thingy acting up and it's not the carb. if you watch it you can often see the bad one move or move something just before it acts up.

X2 on all Jims qqs, and can you describe what it's doing?

[Cr33p3r]

Keith, Holleys are very suctseptable to BPCs (Barometric Pressure Changes) that we encounter at our altitude, They can run great one minute and like crap the next. With this type of problem you are encountering it could be multiple things; Float levels, Metering Valve, Jets, Vacuum, improper nozzle size. Improper float levels can do 1 of 2 things either starve the motor or flood the motor. Metering valves get blown on Holleys a lot and they meter the flow of fuel in to the venturi, Jets also meter the amount of fuel too small ad not enough fuel goes in and too big and the a rich or flooding occurs, Vacuum I mention because a some Holleys have vacuum secondary's (the two rear venturis)If there is a problem there it will either open the secondary's or not and they will flood also a vacuum leak can cause a bad idle they either suck too much air in or blow air out.

I would start by doing a good look over everything to see if anything is obvious when it is running and if you don't find anything I would start by replacing the metering valve those are usually the first thing to go. Changing the jets is a hit or miss and takes a lot of time because you take a reading om the vacuum pressure, idle speed, and rpms as well as how the motor runs under load. Then you use a chart to figure out which direction you need to go up or down in sizing and do it all over again all the while you keep going thru fuel bowl gaskets about every second time of opening the fuel bowls.

When we did Geneva creek and we all were playing in the muddy water hole Happy sucked a bunch of that muddy water into his carb, It was a good thing he had the Edelbrock carb because it was a simple fix, if it would have been a Holley it would been a lot more difficult due to all the places that are metered on them. If you need more info let me know and hope this helps!

[transplant87]

So what happened was is I pulled up to this kid on chambers in Colfax she started reving his moter and wanted to race and I took of and hit speed limte and slowed down. When i got home I took of the air cleaner I noticed fuel squirting out of my secondary float breather and I'm getting really bad mpg and running like crap

[transplant87]

Freaky. I want to trade my holly for and edlebrock. I've had nothing but problems with it

[KnuckleHead]

That was a fun mud hole... have fixed that problem for the next time.
I agree with the changes part. I know with my Edlebrock I have problems in the winter time. With the change from warm days to cold its never the same from day to day. Seems carbs like warmer days better, at least mine does. The rig starts easier and runs better on a warm day and takes forever to start on cold ones.
I know Keith is running the holy on a newer 454 that was TBI. It always seems to fire right up on the first try but seems like its running rich. We put a aftermarket electric carb fuel pump as the block has no spot for a mechanical pump. There is also a aftermarket regulator on it as it seemed it was putting out to much fuel.
Hope that helps alittle for anyone with an idea.

[Jim]

So what happened was is I pulled up to this kid on chambers in Colfax she started reving his moter and wanted to race and I took of and hit speed limte and slowed down. When i got home I took of the air cleaner I noticed fuel squirting out of my secondary float breather and I'm getting really bad mpg and running like crap

Could there be any "stuck" part in the carb? When moving the throttle & choke plates full range of motion - do they return to where they should. Is this a dual float carb setup? If yes, could the float mechanism for the secondary be stuck "open" and thus overflowing (and the overflow would be routed down the throat vs. out onto a hot intake manifold). Visible fuel flow would be my first focus - good you noticed it.

[Hypoid]

I noticed fuel squirting out of my secondary float breatherYup, the secondary needle valve is stuck open. Try tapping on the carb bowl, next to the needle valve, with a screwdriver handle. Second choice would be float adjustment.

[Fordguy77]

Yup, the secondary needle valve is stuck open. Try tapping on the carb bowl, next to the needle valve, with a screwdriver handle. Second choice would be float adjustment.
X2, Might not hurt to give it a good cleaning either.

[transplant87]

Tonka toy rebuilt it like 2 months ago and was running great

[Fordguy77]

Tonka you rebuilt it like 2 months ago and was running great
Well, just throwing things out there, somethings changed, and i typically try to work from simplest/cheapest to hardest/expensive

[Hypoid]

Tonka you rebuilt it like 2 months ago and was running great
That is fine and well! What pressure is the regulator set for?

[transplant87]

5.5psi

[Hypoid]

It still sounds like you have a float stuck at the bottom of the fuel bowl.

If you decide to adjust the float level, be very gentle about snugging the jam nut. I have stripped the threads out of the fuel bowl that way.

[transplant87]

It don't have a adjustment screw

[Hypoid]

How do you adjust the float and the fuel level inside the carb?

[transplant87]

Not sure. I don't know much about carbs

[Jim]

How do you adjust the float and the fuel level inside the carb?

While it's been a pinch since I've been into an automobile class carb, some might have a brass tang/tab that depresses the needle to which the tang/tab may be bent to allow for adjustment.

[Java]

Generally there is a tab on it that you bend like Jim said. You could also have a dead float that is full of gas and not floating, all it takes is a pinhole if it's the hollow style. If it was me I'd pick up one of these http://www.summitracing.com/search/Brand/Holley/Part-Type/Carburetor-Rebuild-Kits/Product-Line/Holley-Remanufactured-Carburetor-Renew-Kits/?autoview=SKU&gclid=CNbbpKKr57UCFcdDMgodx2AAyA some cleaner and compressed air and rebuild it. Kits like that are really just parts swapping, and you'd be surprised how easy it really is to rebuild them.