Asa":4gpwe8eb said:Time to put this together. What size ball valve should I be using?
Check Balls
Check balls are often placed in the wrong hole, so don’t assume you will find the correct size in the particular hole.
The bigger check ball goes in the main discharge.
Once the check balls are in place you will need to test them to make sure they seal correctly. Use a test fluid, like carburetor cleaner (NOT WD-40), and a small punch to gently hold down the ball on it’s seat and depress the pump in it’s well by hand. If you get a hydraulic lock then you are good to go. On holes other than the accelerator pump simply watch that the fluid doesn’t leak out.
When the check ball isn’t sealing, then you will need to re-size the hole by tapping on the check ball a couple of times. DO NOT use the new check ball for this. It could become mall formed. Use the old check ball if it isn’t corroded or beat up
YF Check Weight
Carter YF & YFA Check Ball & Check Weight Placement
1st of all we should know what the check ball & check weight is for. When you press on the gas to accelerate, the engine needs an extra spurt of gas to get you accelerated until the cruise circuit can catch up. This is where the accelerator pump circuit comes in play. Pressing the accelerator causes the accelerator pump diaphragm to move up forcing a small amount of fuel out through the main discharge. The force of this fuel forces the check ball and check weight, or in some cases just the check weight up, allowing fuel to flow through the main discharge. When gas isn't being pushed out the discharge, the check ball closes off the fuel so that vacuum from the intake doesn't siphon fuel through the main discharge.
Some Carter YF carburetors have a check ball with a check weight on top of it.
Namely,
Carter YF Carburetor 1971-74 Ford
1971-74 Ford 200, 240
See # 24 & 25 in the illustration below. Notice that the check weight is rectangular shaped. This check weight is nothing more than a weight. It probably weighs less than 1 gram, but that's OK. Too heavy and the check ball would not lift off the hole.
Carter YF Carburetor Check BallOther YF & YFA's might have just a check weight, but this check weight is tapered on the end and this taper acts the same as a check ball does. See #26 in the illustration.
Carter YF Check WeightCheck weight w/o check ball. There are 3 different lengths depending on the carburetor. Most use this one captioned here. After placing in the main discharge you should have 1/16 - 1/8" free space for the check weight to lift off the seat. You can grind the check weight down to fit.
Carter YF check weight
Check weight w/check ball.
Make sure you have about 1/16" - 1/8" of free space for the check ball to lift up.
If you need more, simply grind down the check weight to fit.
Asa":1ce7f12g said:Huh, well that's an issue.
Two balls in this kit were .186" ish, one is .14" and I have one of the triangular check weights.
I wonder where I can get a ball bearing that size today.
Make sure you have about 1/16" - 1/8" of free space for the check ball to lift up.
If you need more, simply grind down the check weight to fit.
Asa":3mlcf8w5 said:
Too late, X. Found a local bearing supply place that had them.
Asa":3mlcf8w5 said:I will say, though, I've yet to see a kit with the lifter seals in it. Roughly middle of the image?
http://www.carburetor-parts.com/YFA-Exp ... _1855.html
Carter YF lifter seal. This helps seal the lifter hole so that fuel doesn't spill down the shaft. There are 2 seals used here. A 1/16" (this one) and a thinner 1/64" seal.
Carter YFA, 1 barrel pump lifter link gasket. The pump link requires two different gaskets. This is the thinner of the two. 1/64". There is also a thicker 1/16" gasket that is used on most YF carburetors along with this gasket.