Leak in Carburetor

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1970Dart198

1970Dart198

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I noticed small drips of fuel accumulating on the intake manifold. The marks are centered above the fuel bowl. My diagnosis is that I have a leaky fuel bowl gasket.

I'm buying a Daytona Carburetor Rebuilding kit for my Holley 1920 Single Barrel (remanufactured!). Since I'm in college and I don't have the time or facilities to rebuild the entire carb, is it wise to just unscrew the fuel bowl and remove and replace just that gasket? Everything else is fine on the carb.

I plan to eventually use the entire rebuild kit, but just to stop the small leak is this minor repair worth it? Or is the carb so simple that I can rebuild the entire thing in my dorm room? I have all the tools necessary.
 

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The Holley 1920 is an easy rebuild, I did the one on my 66 Dart two years ago and it only took about an hour, that also included flushing it out with carb cleaner to get rid of any contaminants that might be in the ports. I would suggest rebuilding it all at once to get it done and over with. The most important thing to remember is to take you time and lay everything out neat and orderly, and follow the directions that come with the rebuild kit. For organizing the stuff you could use an old tv dinner dish while taking it apart. Once you rebuild it, just remember to check all of the carb screws (especially the float bowl screws) and intake mounting bolts periodically to make sure they haven't vibrated loose over time, doing that only takes a few seconds and can be done at the same time that your checking your oil. For now you could try snugging down the float bowl screws to see if that stops the leak, it may work, just don't go so tight that you strip out the screw holes.
It would also be a good idea while your doing the carb work, to replace the fuel filter and replace the hoses that go with it, with the new ethanol resistant hoses that can be purchased at the parts store for short money.

Paul
 
if you are in a hurry. the outside doesnt to real clean. but inside does. and the gasket surfaces do have to be clean. and mostly the air holes need to be clean. dont over tighten the bolts, just a little more than snug should be fine. then recheck after a few heat cycles. set the float level at what is called out. dont out think your self.
 
Those always leak there. Take the bowl off and look at the ears, they are most likely bent back from overtightening. Grind down the edges of the screw ears very slightly so they dont contact body so they compress the gasket again. Should be good to go.
 
I rebuilt a 1920 with that kit in less than 2 hours while cleaning it. It's pretty much all one piece. Once the fuel bowl is off, everything else is right there (kinda). I also had never rebuilt a carb before and figured it all out easily enough with 0 experience doing it. The most painful was the $50 price tag on the rebuild kit.
 
All good advice. Besides fuel bowl leaks, I had an accelerator pump diaphragm fail, around the time they started putting ethanol in fuel. The problem with rebuilding a 1920 is that it has a sealed "metering block". Read posts for how to blow out the idle air circuit w/ air. I think some have run a thin wire thru the passages too.
 
Hi ! If accelerator pump diaphragm fails it drips fuel like yours do, so its wise to change that wile your at it. Greetings from Sweden ))
 
So I'm buying a Holley 1920 Rebuild Kit from Mike's Carburetor. Stock #K4093. I was told that the float 100-14, the nitrophyl float, will not fit. Mike's Carb does not have the other ones that will fit.

Walker products has a few floats, including the 100-14. The other floats are the 100-86, which is also nitrophyl, while the other float, the 100-39 is brass. Which of the two floats should I order from Walker Products?

My Holley 1920 Carb # is 6156 and its off of a 198 ci slant six.

https://buy.walkerproducts.com/carb...holley-1bbl-1904-4-carburetor-components.html
 
Unless there is a problem with the float, you shouldn't have to replace it. If the car was running good to begin with, and the only problem was the leaky bowl gasket, then I would just rebuild the carb with the new rebuild kit and reuse the float that is in the carb now. It should work fine and you'll save a few dollars on the float.

Paul
 
Sounds good, I'll think i'll try that.

I'll just clean the carb well and rebuild it properly, unlike the remanufactured one I am using, i'll rebuild it so it wont leak.

Thanks
 
Fixed! I changed the fuel bowl gasket and upon inspection inside the bowl, everything was actually pretty clean! (the Carb is about two years old) I replaced the intake manifold to carb gasket as well. The Intake-Carb gasket was paper thin, (and probably the reason for my bogged acceleration) while the new gasket was pretty thick and sturdy.

Now the car idles much nicer, and there is no fuel leak from the bowl.

Thank you for all of your suggestions!
 
Great work! Nice to hear it was an easy fix, just remember to recheck the bowl screws and carb/intake gasket bolts after a few days of running to make sure they are still tight and not leaking.

Paul
 
Yeah about that, the new gasket was MUCH thicker and the two bolts were JUST long enough to torque down.

I still dont like having such little thread holding the carb onto the manifold, so I'm going to go to a hardware store and buy longer bolts, some washers and lockwashers to help hold the carb in place with the thicker gasket.

The old gasket was literally paper thin, (I could break it with two fingers), that was probably why I was having a hard hot-start for so long! My main fear is when I drive, having the bolt shake loose and loose vacuum pressure and stall out on the highway.

Would grade 8 bolts suffice? I know those are pretty hard, and I DONT want to strip the threads on my cast-iron intake manifold.
 
I had the same issue with the thin carb base gasket, my kit came with two different gaskets. I used the thicker one like I have in the past with my Darts. As for the bolts, I had one long and one short, fortunately I have a hardware supply from past cars that I use every now and again, and I had the correct longer bolt in stock. Having the carb held down by two or three bolt threads, I would be more worried about having the carb come loose and twisting enough to jamb the linkage open while I'm driving. Any bolt is better than what you have now, they don't have to be hardened because your not going to wrench them down like lug nuts, you just want them to be tight to hold the carb in place. A good auto parts store should be able to get you the correct bolts that you need for it at a reasonable price.
Paul
 
You can always get some longer bolts and grind or cut them shorter to get a good number of threads into the manifold, if you cannot get the exact length. And yes, grade 8 is overkill; grade 5 is far strong enough to torque down enouhg to bust the carb! Having the right bolt finish or a thread treatment to prevent bolts corroded in-manifold is more important, IMO. You could use some blue locktite for some extra security without too much torque on the bolts, but that seems kinda unusual for carb bolts.
 
I'm glad you fixed it. I'm not a fan of those carbs at all but I'm pretty impressed with the one on my '73 Valiant. It's been on there so long that it's covered in greasy dirt blowing off the engine and still works well, although the accel. pump is starting to weep and it started having these 'spells" last year where it barely run periodically. I scraped the dirt off and it's the original '73 carb it came with.
 
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