Originally Posted by Chad Simpkins
I have a '58 3200 that I am currently restoring. I started with three Rochester Model B cores. I figured between the three I should end up with one solid carburetor. THIS IS GENERALLY A RECIPE FOR DISASTER, FIND THE CORRECT CARB BY NUMBER AND REBUILD IT

Of the three bases with the throttle valve only one was good. The other two were rusted around the opening for the idle circuit which enlarges the opening causing them to be impossible to dial in at idle. Is this a common issue? Can the other two bases be repaired and is it worth it? POSSIBLE, BUT CERTAINLY NOT WORTH THE COST OF A ROCHESTER B

Each of the three donors had different main jet sizes. They were 50, 55 and 56. When the throttle valve is closed I am getting fuel that is not atomized (i.e. liquid fuel) coming out of the crossbar and the carburetor make a gurgling sound. I have read that the correct jet size for a 235 in a '58 truck is a 44 or 46.

THE ORIGINAL JET FOR THE ORIGINAL ROCHESTER B ON A 1958 TRUCK WITH 235 IS A 58

I am at 6000ft elevation and so I usually use a smaller jet.

AT 6000 FEET, DROPPING THE JET DIAMETER BY 0.002 USED TO BE A GOOD IDEA. HOWEVER, IF YOU MUST USE E-10, THE STOCK JETTING WOULD BE ABOUT PERFECT

I have ordered a 42, 44 and 46 and I am waiting on them to arrive. When I went from the 56 to the 50 main jet the gurgling and amount of fuel dropped a lot. Do you think that having the correct 44 or so jet will eliminate this problem?

SEE ABOVE, JETS THIS SMALL WILL PROBABLY NOT RUN!

Finally, when I was using one of the carburetors I was having it bog like the accelerator pump wasn't working. I took it apart and started troubleshooting. All of the ports were clear and the pump was pumping fuel, but there was no pump jet in the throat of the carburetor!

PUMP JETS ON MANY LATER CARBS WERE PRESSED IN, NOT SCREW IN, TO REDUCE MANUFACTURING COSTS

The casting for the air horn was flat where the port should have been. I checked the other two and found one other was the same. I ended up using the third that has a pump jet and the accelerator pump issues and the bogging went away. I can't figure out why these two carbs don't have pump jets. Are they meant to be secondary carburetors or are they meant to be used on generators or other implements where an accelerator pump would not be needed?

I HAVE NO RECORD OF ROCHESTER EVER SELLING THE B FOR USE ON OTHER THAN PASSENGER, TRUCK, OR MARINE; AND THERE WERE NO USES AS A SECONDARY CARBURETOR

Thanks,
Chad

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
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