1954 Chev truck Carburetor Question

[Darthintel]

I just purchased a 1954 Chev 3100 5 window truck with all original drive train this weekend.
The engine starts up great, but doesn't idle very well without a little choke being applied. It accelerates very good - just transition from idle is bad.
When coming to a stop the engine will stall. But start right up.

The previous owner told me the carb was just rebuilt. From looking at pictures, it appears to be a Carter YF - I don't think this is the original carb. I think this is off of a 1957 or later chev vehicle or Willys jeep.
Any information on this carb would be helpful.

I'm thinking it's a vacuum leak and will check the following.
1. The base of the carb there's a plugged vacuum line. most likely it was for the wipers. It looks like it's plugged with putty. I'll check this for a leak with carb cleaner.
2. The idle mixture will be adjusted to see if it could be improved.
3. Check the distributor vacuum line for tightness / any leaks.
4. Spray carb cleaner around the base of the carb and intake to check for leaks.
5. Remove carb and check all sealing surfaces.
6. Check intake manifold bolts for tightness.
7. Take to shop - (last resort)

Any other suggestions?

[geezer#99]

Might not be a carb problem!
Is the distributor advancing correctly. The mechanical and the vac advance.

[Darthintel]

I warmed up the engine and adjusted the idle speed, and idle air mixture. Seems to idle better now. To answer a question, when I open the throttle, I can see the distributor rotate, so I assume the vacuum advance is working. Also, engine accelerates just fine. I want it to idle better. Getting a new exhaust put on ad the muffler is crushed- could also be problematic.

[geezer#99]

Those distributors rotate like that. That’s the way they Mechanically advance.
The vac advance pot on yours could be kaput. And create a vacuum leak which causes your motor quitting problem.

[cadillac_al]

Back in the day the old guys would say " you gotta feed your fire". People would have to use a little choke to make the engine run better because the points were going bad. Back then a lot of carbs got rebuilt because of bad points or bad point adjustment. That's what I think of when an older vehicle needs choke to run good.

[Darthintel]

Looks like I need to learn how to install / adjust points again.
I'll be replacing the spark plugs, plug wires, distributor cap, rotor, points, check timing, and check for vacuum leaks.
I've ordered the shop repair manual and factory assembly manual.

Time to go back to school on old school engine mechanicals.

[mattfranklin]

The previous owner says it was rebuilt. Did he forget anything? Did he soak it in a bucket of the good stuff to remove all traces of varnish and gunk?

Techron Concentrate is good for cleaning fuel system deposits gently over time (like over the lifetime of one or two tankfuls) without harming the engine. I have lots of experience of it in dyno testing with port fuel injected engines. It works great there at removing deposits.

Dumping a bottle into your fuel tank is one of the cheapest easiest things you can do before ripping into the hardware.

[Darthintel]

Anyone buy the electronic switch that replaces the points?

[geezer#99]

If you mean ‘pertronix’ then yes, but it was for a 250.
Fairly easy to install.

There is another dizzy too.
An hei.

If you want it to look stock use the Petronix.
If you don’t care one way or the other use an hei.

[Dead Parrot]

If my several pounds of GM Delco Carburetor book is correct, your truck came with a Rochester Model B. I think the YF was a common replacement.

When adjusting your points don't forget that will change the timing.

One good thing about your truck is checking all of the rubber hoses for vacuum leaks shouldn't take long.

['68OrangeSunshine]

Look online or in thrift shops for a Dwell/Tach/Voltmeter. Sears used to sell them. Points tune-ups are easy then.

[Darthintel]

I agree when new the truck came with a Rockchester carb. This is a Carter YF.
I will most likely buy a new distributor assembly with the electronic switch and new coil, to still look stock but have the convenience of electronic switching.