Setting Float Carb ETW1

[NAM VET]

When I was searching for info and pics on how to set my carb's float, there weren't many pics of all this. So I am posting some info that may be helpful for others doing this. First some comments: This is the only time I have been "inside" my M 37's carb, and is only how I did it. There are other thoughts on important considerations on this forum. My original problem was a failing Facet 24 V pump giving erratic fuel pressures. My carb was perfectly rebuilt by Charles T's team several years ago, so it was perfect other than my incorrect needle and seat setting, since I had replaced his flat face needle/seat with the triangular one, for some un-recalled dumb reason

My symptoms after a new low pressure Facet with a low pressure fuel regulator was an inability to idle at all. More on that later.

There are screws that hold the carb top on the bowl, the two longer at at the vacuum position site, obvious as it is a thicker cover. There are two "bolts" from below, hard to reach, so I unscrewed the two vent lines to have access to them. Need a small 11/32 wrench for these. Before I did anything, I draped a cloth around the base of my carb, since too often I have lost small parts into inaccessible places. It is tricky to remove and reinstall these two small bolts from below.

Then remove the three bolts holding the carb top to the "elbow." 9/16 head bolts. Then unscrew the long idle needle on the top of the bowl, it has to be removed to lift off the carb top. When you have it out, blow out the tiny holes in the needle. My carb top lifted off easily, but beware of the one inch tiny spring in the "step up piston rod". Lay the carb top off to the side. Carefully scrapped of the bits of gasket.

I removed the twin float, careful to not lose the tiny shaft and the bent spring that holds it down into the needle/seat's slot. Then stuffed some rag into the intake, to avoid dropping parts down into there. Wiped out the carb bowl with small clean rag.

I had made up my float gage out of an aluminum bar. The float level for the triangular needle/seat is 5/64 below the carb bowl's top, it is 1/16 inch lower for the "flat face" needle and seat. The float level must be set with the needle/seat fitting snug and seated. I marked the brass nut on that with a file so if I ever have to remove it, I can tell where it needs to be in just right.

I made my gage on a fine grit stone on my grinder, and when it got close, I finished it with a file. The Diagram on page 44 of the Ordnance Carb manual is not to scale for 5/64, although it is correct for the length of the gage, and where to put the projections for the float. The floats have a seam in the middle, which is 15 thousands taller than the float body. Set the float NOT on the seam. To ensure my float gage was correct and even for 5/64, I rolled a drill of that diameter back and forth on a block, but 5/64 is also precisely 2mm if you have that drill.

It is important to not bend the float connection, making them uneven, they have to be exactly symmetrical, not one taller than the other. I used a wide tip needle nose pliers to hold only the float connection, then bent the "flap" with another pliers. I did not want to touch the floats themselves, and be sure to not crimp the pins two tiny holes. I did and had to use an ice pick to every so slighly open them up so the pin would move and allow the float to move.

I used my finger to press down on the needle/seat and kept checking if the float would rise and just touch my gage. It took a few trips to my work bench.

In order to set the carb top back on, I had to loosen the carb's neck support bracket nuts to allow the neck to give room to put the top back on, and snug that down. Only this way could I have room to insert that big gasket and get the three big bolts to engage their threads. The tiny spring on the plunger has to fit into a short recess in that, so I pulled out the spring and used a tiny dab of grease to hold it into its recess so it did not fall out when putting the carb top back on.

Reattached the vent connections, attached the gas line, and when I still had no idle, realized I had put the needle in backwards, so took ten minutes to pull it all off and put the needle in correctly, tip out, reset the floats again, and then my truck idled and ran perfectly.

Gasket set was ten bucks, came sealed in a package dated 1955, but was fine, using only the carb bowl and neck gasket.

So, here are a few pics of all this in the post below. Hal, aka NAM VET

[NAM VET]

[url=https://postimg.cc/7GHwfpGF][img]h ... .jpg[/img][/url]

[NAM VET]

don't touch the floats when bending the flap, only the connection and the "flap" that regulates the needle.
[url=https://postimg.cc/kB696NGg][img]h ... .jpg[/img][/url]

[NAM VET]

press the "flap" against the needle with enough pressure to seat it, and then see if the floats just touch the gage projections. I couldn't take a pic of that.

hal
[url=https://postimg.cc/Jy72Jmx5][img]h ... .jpg[/img][/url]

[Cal_Gary]

That is some great info Hal-thanks for sharing!
Gary

[Argie1978]

Hello Hal.
Allow me to to fix the links for the pictures in your posts as somehow they don't work when clicking

don't touch the floats when bending the flap, only the connection and the "flap" that regulates the needle.

press the "flap" against the needle with enough pressure to seat it, and then see if the floats just touch the gage projections. I couldn't take a pic of that.

hal

Appreciate. This is good info as everything that comes to the carb, its issues and how we can avoid headaches.

Sebastian