I noticed this is causing a vacuum leak and it is leaking gas. I have the 1904 holley carb, the motor is a 215. the leak is coming from the rivet that holds the thottle arm on the carb. my question is how can I fix this. do I need to drill out the old rivet and put in a new rivet? the carb is working great but it seems that it is causing a vacuum leak and a gas leak. any help would be great thanks.
Just an opinion, but I'd try to find the source of the gas before I did anything to the base. It's probably a leaky bowl valve ***embly (needle and seat - part #21 below) or a mis-adjusted float. Either of these things, and some others, will cause the float bowl to over-fill when the engine is shut off and dribble fuel down through the overflow onto the ****erfly where it leaks out the throttle shaft. Boil the carb out and put a kit in it. Don't go re-manufactured unless you absolutely have to. Rebuild the original carburetor! Remanufactured carburetors are often "compromised" by new-made parts that are not like the old ones and are very often jetted differently than the original. Oh, and don't trade in the original carb under any cir***stances! Keep it for a source of parts...you'll be glad you did! Don't worry too much about a vacuum leak at the shaft unless it's got a LOT of freeplay - then replace the base with one with less slop at the shaft. (Most cities and towns have at least one carburetor rebuild shop that's been in business for many years. These places often have "core" carbs and/or parts you'll need to get your original one up and running again. You'll never find parts for obsolete carbs at parts stores or wrecking yards, but these guys have barrels full of 'em and are usually glad to part with 'em.) Hope this helps.
That does sound like the problem. when I went to shut it off is when it leaks I also noticed it when I checked it with a vacuum gauge at the manifold when I went to put the vacuum hose back on. I will be taking a look at those 2 things. thanks oh how would you adjust the float bowl? I have the ford manual for my car. thanks!! I might have a couple more questions this weekend.
The float level is set when you re***emble the carburetor after a rebuild. You might be able to dis***emble the carb, set the float level and then re***emble it...but don't count on it. The old bowl gaskets will probably not allow re-use. Your factory manual shows how the float drop is measured and set. Do not use the float drop dimensions given in the carburetor rebuild kit. Use the dimension given in your Ford factory repair manual. I have run into many errors in this dimension over the years...the kit information was always the problem. I have an 8N tractor with a Funk 6-cylinder flathead conversion that uses this carb. It's a very robust and easy to work on carburetor...good for a beginner to learn on. Go easy bending the tabs on the float also. The br*** is old and brittle...just like me! Good luck!
Check your Ford manual and run a fuel pressure check, excess fuel pressure can cause the problem you are having you may have to add a pressure regulator.
Jeff is right. Too much fuel pressure will force fuel past the needle and seat, over-filling the float bowl and out the overflow into the throat of the carb. Good catch, Jeff!
yeah sounds like the problem cause with the air cleaner off there is some small amount of smoke coming out of the carb after the car is shut off!
Fuel pressure guages are available at auto parts stores. Just plumb it into your fuel line between the fuel pump and the carburetor, permanently or temporarily, and read it with the engine running. It can also tell you the story of how quickly the pressure bleeds off after the engine stops running. Your manual will tell you what proper fuel pressure should be. Be especially wary if you're running an electric fuel pump. They come in two kinds: low pressure and high pressure. You'll want to use a low pressure electric pump along with an adjustable fuel pressure regulator. As I recall early Fords like 2 to 3 pounds of fuel pressure. Your manual will give you the specific pressure for your car/engine. Also... Speaking of electric fuel pumps. Be absolutely sure to install a fresh flexible fuel line between the car's hard line and the fuel pump. Your rear-mounted electric fuel pump will pressurize that line and IT IS NOT DESIGNED TO OPERATE UNDER PRESSURE! If that line bursts while you are driving, your car will burn to the ground before you know what's happening! A better fix is to replace it with a length of modern fuel line which IS designed to operate under pressure. You'll need two br*** fittings, two hose clamps and an appropriate length of modern fuel line to get the job done. Cheap insurance! Just a whisper of warning to the wise...
When I replaced the mechanical fuel pump on my 223 - I had to add a pressure regulator to the line. The new pump was rated at 5-7 psi. I've heard the 1904 is good at even 1psi - 3 max. Before I put the regulator in the pump was flooding the float all the time.
update: Here is what was causing the carb to flood if you take the float bowl off, you will see the float take that piece off. Now, if you take off the piece that holds the needle. There is a plate with 5 screws. Those came loose causing gas to flood past the plate and flood the carb. so easy fix but it took me a couple trys of taking apart the carb to find out what was going on. So It wasn't the float level after all. I wonder if anyone else hear has had the same problem? is it common for these screws to come loose?
its a good idea to go ahead and replace all the rubber fuel hose every couple years. cheap insurance . seen many engine fire because the hose at the fuel filter or at the carb started seeping.
sloppy rebuild! no if you overtighten the screws you will warp the plate. my feul lines are new wasnt the feul lines.
Vein: I didn't mean to imply that YOUR rebuild was sloppy, but rather that whomever worked on the carburetor BEFORE YOU didn't properly tighten the screws. And yes, over-tightening can be even worse than under-tightening, but neither of these is proper. Glad you finally got your problem under control.
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