1950 Willys Truck re-rebuild by 50wllystrk

4 minute(s) of a 620 minute read

Scooter, I can tell you're just aching to raise your hand with the answer/Knowledge is power, and you can feel it.

Let's get past the next couple pictures, then we'll answer the "black plastic cap" question...

First let's look at the choke thermostat in the "cold" condition. I made a quick piece of linkage to hook the thermostat to the choke mechanism on the carb. Notice the choke plate is in the closed position on the carb. This is the cold start position.

When the idea of adjusting the automatic choke has been mentioned, here is the first step of adjustment. The linkage I made that connects the choke thermostat to the carburetor has a purpose built shape to it. I could have made a straight linkage, but, just as the factory used, I put a couple bends into it. By either bending the linkage more, or, straightening it out, I can adjust the time it will take to begin opening the choke plate on warm up.

A simple form of adjustment, just easily overlooked if one doesn't understand the concept.

In this next picture, I did nothing to the carb or to the linkage. By using the lighter I heated the choke thermostat. As it heated up, the linkage slowly rose upwards and opened the choke plate to normal engine operating temperature. How cool,, all this happens everyday, everytime we start the vehicle.

Note.... on the engine, the aluminum base of the choke thermostat absorbs the heat and transfers it the the wound flat coil. There is a shield that snaps over the top to keep the heat within. If there was no cover, the wind from the fan blade would cool the choke thermostat and it wouldn't open the choke plate properly.

Note... I colored one piece of linkage black and another one I colored red. The black represents more choke linkage. The black one hooks to a vacuum diaphram canister. This canister leads to the next picture having to do with the "choke pull off". This is the item that will open the choke plate enough to allow the engine to get air at cold start. Study the last couple pics and see if you can tell how it opens the choke plate at start up.

Note... I mentioned the purpose of the black linkage, but didn't mention the purpose of the red linkage...and ideas?

I hated homework in school, yuck! But I know now that it was a way to demonstrate that I had a grasp of the theory I was to absorb in school. The red linkage has everything to do with the Holley carb we already covered.

In the real world you're gonna come across different ways of accomplishing the same function. If you understand the theory, the different design won't bother you. If you don't understand the theory, forget it. you could be there for a while.

Scooter402, this is the perfect time, having to do with different designsaccomplishing the same function. Want to answer the black plastic cap thingy?