Catching up on my thread. I missed a bunch of these responses. I still haven't gotten it out to drive again. I plan to adjust the mixture screw and see if that helps. The engine has probably broken in at this point and I didn't check the adjustment since last year. I would like to get a vacuum gauge on it.

Also, I wasn't clear in one of my answers about the carb rebuild. It was rebuilt last year when I first started the engine not rebuilt between seasons. The float is plastic and does not have any holes or leaks in it that I can tell when I last took the float cover off.

A few questions:

I want to put a nipple on the intake to adjust the mixture screw based on the vacuum instead of my ear since I wear hearing aids and loud noises like a running engine get managed by the sound processor in the hearing aids so it's hard to hear subtle changes in rpm etc. It looks like there is a 1/8" NPT fine thread port on the intake. What is the thread pitch? 1962 223. I can put a nipple on there to get a vacuum gauge on.

When discussing jumping the truck there was a reference to the key being in the "run" or "start" positions. I have 3 positions on my key. All the way to the left sees to be accessory, center is "off" but the starter button will still turn the engine over and to the right which I think is "run" where the truck will start when the starter button is pushed. Do I have the nomenclature confused? Basically I only have "off" and "run" when it comes to starting the engine with the push button.

I thought that with the key turned all
the way to the right in the "run" position if the positive cable went to the starter and the negative cable to the left post on the solenoid that comes straight off the battery (when facing the solenoid meaning the post on the passenger side of the solenoid) that I would've directly powering the starter and not have to worry about back feeding. Do I have that right?

The carb has a metal float cover and I have no idea how to know what the float level is or how to adjust it. I have seen glass bowls float covers on some of these carbs is that a good "upgrade" to be able to see the float?

If I am lucky just the mixture screw needs to be adjusted. Raining again tomorrow but if I can get the right sized nipple at the hardware store I can try and get the mixture adjusted and then try it again on Sunday.

 

When discussing the jumping without back feeding: The "run" means ignition coil is powered, but not cranking starter motor. "start" means crank (in this case, pushing the starter button, something you would not do when jumping in this way). Since you are 6V, you would be positive ground. You connect the positive jump lead to the battery (+) terminal (or a good ground). You connect/touch the negative jump lead to the terminal on the starter solenoid that has the fat wire going to the starter motor.

As for the manifold, I believe you are correct that it is 1/8 NPT. 1/8 NPT is a tapered thread (for self sealing) and unlike fastener threads, isn't defined by coarse or fine thread variants. It is simply understood to be 27 tpi. You remove the 1/8 NTP pipe plug from the manifold and then can install any male 1/8 NTP fitting that adapts to whatever is convenient for your vacuum gauge. An interesting rabbit hole: https://www.ford-trucks.com/forums/1...s-purpose.html

Now, on to your 1904 - Yes, a glass bowl was used: https://www.ebay.com/itm/236770762280

A glass bowl is not necessary to adjust your float, and some see it as a safety issue as glass breaks easily and would then dump fuel all over. I'm of the opinion that if you want to run a glass cover, go for it! It was a marketing feature done by Holley:


As for float height adjustment, you can use a float gauge like this MC-157 to set the float drop and float height per the Holley 1904 manuals: https://www.ebay.com/itm/186781434554




Or you can focus on the float height by inverting the carburetor and measuring 13/64 from the inside of the bowl to the tip of the float (farthest form the fulcrum).

 

Yeah this kinda sounds like a classic hot restart issue on older carb setups.

I've seen a few cases where it starts fine cold, but after a short stop it just struggles to catch again. Usually ends up being more fuel/heat related than battery or charging stuff.

Might be worth looking at how it behaves once it’s warmed up, but yeah these ones can be a bit tricky to nail down sometimes.

 

Yes tricky indeed!

You don't know if its not firing due to heat causing fuel expansion out of the carburator thus flooding
due to wet plugs. Or the fuel boiling off out of the carburetor causing lean start conditions. Or even tempersature related ignition coil issues. Maybe put your old coil back in for a test. I would start by giving it a good drive. Return back home. But after shutting the engine off open the hood and let it set for 5 to 10 minutes. Does it start easier?

About using a vacuum gauge. On You Tube Thunderhead 289 has a really good video on hard/hot starting discussion and how to adjust your idle screw(s) using a vacuum gauge. Different engine and carburetor and you have just one mix screw but the idea should be about the same.

 

Epic responses as always!!

I don't think at $185 a glass bowl is in my future!

Will Check the idle mixture and vacuum first and see what happens. If no change will do the float adjustment. I will probably do the float adjustment anyway at some point soon but if I can get it back on the road without taking everything off that would be great. Super tight on time and too many projects. My Camaro is at the Autobody shop getting repainted and I have been down there daily trying to help out and trouble shoot a bunch of small stuff to fix....

 

It's not clear in the video but this guy sells that controller unit for Carb tuning. It is super slick. If you have a Holley or Edelbrock carb it is definitely worth a look.

https://thecarbcheater.com/

 

Boiling fuel is a real problem in carbs these days. Like mentioned above I would check the flote and instal an insulated spacer the help minimize hear absorption.

 

Are you running any type of fuel filter?

I know some guys frown upon them, but you might try putting one of the clear fuel filter between your pump and tank. I was having similar issues to what you describe with hard or failure to start once warmed up.

When I put the filter on, I could see that I was getting rust particles in the filter. But I could also see that the truck would run and idle just fine, but was sucking the filter nearly dry. Which also meant I had air entering the system. If I left the truck sit for several hours the filter would gradually refill and the truck would start with no issue.

I ended up putting a new tank in and checking all fuel line connections.

Truck restarts fine now (hot or cold) and I can visually see that the filter remains full.

 

Thanks and great idea! So good an idea that I actually did that! I was having fuel delivery issues with my fuel pump when I first got it running. New tank, all new lines and fittings etc. I had 3 bad fuel pumps before I found a good one I believe and the clear filter helped my figure out if I was getting enough fuel. It stays full now but next time I park and start I will open the hood and check as I haven't done that with this problem.

Believe it or not I still haven't gotten it out for a test drive. The weather has been too wet or I have not had a local enough drive to give it a try.

I did buy the float bowl tool off of eBay and got it yesterday. I will try that adjustment when I catch a break if adjusting the mixture screw doesn't do it. I am loathe to take the carb off if I don't have to.

 

Also, if you’re interested in some 1/8” thick phenolic for carb spacers I can fix you up. I made my own spacers using two layers of phenolic and three gaskets.

 

That would be great! I'll take it!