The Stovebolt Site Forums The Shop Area Engine Shop Close-up picture for adjusting Carter YF 2100S

Can someone (CarbKing?) use the picture below to help this dummy adjust the metering rod his Carter YF 2100S carb. The instructions I have from the rebuild kit and the Motors Truck Repair Manual are a bit obtuse so I've labeled the pic.

For instance, do I "Push down A until B1 just touches C1 or whatever?"

Innards of my Carter YF

Thanks!!

Wally, start by backing off the idle stop screw & then be sure you have & keep the throttle plates closed. That takes one hand. Now, with the other hand push down on the top of the rod that goes down to the acc. pump diaphram. As you push that down slowly watch the plate with the stud for the metering rod come down & it should come to rest just touching the plate below it. IF it doesn't touch, bend the metering rod arm enough to accomplish this. IF & when it does touch, repeat this test & watch the metering rod eyelet & the stud its hanging on. When you get the acc. pump all the way down, the M.R. eyelet should be 'loose' on its stud. Meaning that it is sitting on its bottom end in its bore & so the eyelet top end is no longer whats holding it. There's enough difference in diameters of the stud & eyelet that it'll wiggle & flop around in there when its loose like it should be.
A great pic you made, sorry I left out the letters here, I don't know how to post & view the pic at the same time. How about you teach me how to put letters in a pic now?
Hope this helps. Doug

Doug,

Thanks!! I've played around a bit with it and see the movements you describe. I'll tweak it up and let you know.

Thank goodness the YF is on my lap right now so I can let the Rochester Monojet get me to work tomorrow. More later.

Thanks, again!!

Wally, Keep in mind that the ideal position described is how the carb. was designed to operate in O.E.M. conditions. Now we are using them on different displacement motors, with gas of different B.T.U. & burn characteristics, maybe cam grinds, valve size, head porting, headers, etc. all affecting cylinder filling. So, setting it 'by the book' may not give the best results. Then, if its either lean or rich most all the time, try changing the main jet size. They are the same as AFB models, means aftermarket Edelbrock is the same & these are all easily available. Many times it'll be OK cruising but hesitate, means lean, when accelerating like passing other cars. IF we had an assortment of metering rods, we'd try a smaller 'lower' Diam. rod. Not having that, what can be done is just bend the M.R. arm so the rod is slightly higher up. A small change will have a marked effect. Doug

Wally, Doug's posts are excellent. I can only emphasize his comment about a small change making a marked effect.

Carter used to tweak in metering rod increments of 0.00125 inch.

Another tuning tip is to vary the float adjustment. Adjusting the fuel level plus or minus 1/32 of an inch will make a difference (float adjustment is ALWAYS critical). Don't do more than 1/16 inch higher or 1/8 inch lower than specification.

Jon.