1950 Willys Truck re-rebuild by 50wllystrk

3 minute(s) of a 620 minute read

Now that we've seen the needle and seat, and we've removed it from the carb and along the way we've learned how to adjust it up and down. Now let's look at the float that will be affected by what we do with the needle and seat.

Here is a picture looking into the float bowl. The float in clear view. Look to the right side and the plug to remove to check the fuel level is there also.

By removing the two screws in the back, the float assembly and it's pivot is removed. If I took a good picture, you can see where the float mounting tab makes contact with the needle.

By seeing the mark on the float mounting tab, you can see where the float, once the fuel enter the bowl, raises and pushes the needle upwards to the seat to shut off the fuel entering the bowl.

This next picture should put the hole thing together. Here is the needle and seat just waiting to be pushed up and down by the float.

Over the years I've seen guys get a speck of dirt caught in the needle and seat and have fuel come out the top of the carb. I've had this many times, it's just a part of working on cars and trucks. Over and over I've watched them dissassemble the carb to get to the jets, remove them to clean or replace them.

The jets have nothing to do with the amount of fuel in the float bowl. They have alot to do with the amount of fuel getting from the float bowl to the intake manifold.

I hope by now you all are nodding your heads saying, yeah, that makes sense.

So far the focus has been on the Holley, it's a common carb, so to understand it is a good thing. This hasn't been just to learn the Holley carb so much as a lesson on how all carbs work. Yes, all carbs. They all have a float and needle and seat. They have jets. If they are 4 barrel carbs, they have secondaries that have their ways of opening. They have accelerator pumps, the Holley uses a diaphram, others may use plungers.

As long as the knowledge of how and why a carb works is learned, you'd be amazed at what you can do to get yourself out of a bad situation either in the middle of the woods or in the middle of a traffic jam.

There's still a couple of items to cover on carbs so hang in there.