I didn't pay much attention when I took the carburetor apart as I assumed it would be pretty easy to figure out when it went back together. Well, I have run into something that is less than obvious.
First of all, the accelerator pump is connected to the linkage so that it is fully compressed when the butterflies are closed - this seems backwards to me, but the metering rod is connected to the same plunger mechanism and it is fully closed at idle and fully open at full throttle so it must be right.
I don't have a digital camera handy otherwise I would post a picture, but the spring arrangement on the accelerator pump seems all screwed up. If assembled according to drawings, the accelerator pump is run by the spring action and the linkage only allows the accel pump rod to come up (the linkage is not attached to the rod / only presses down on it when going to an idle). This seems like a lame way to get positive displacement from the pump when stepping on the accelerator.
I moved the spring to between the bottom of the accelerator linkage and a keeper location on the rod and this seems a lot more positive as the rod is not locked to the linkage under tension - in this configuration it works really well, except that the spring is now compressed to the point of being rediculous. I am tempted to button it up and see how it works . . . it is easy to see how the metering rod would never fully seat at idle when assembled the other way - this could explain the way-to-rich idle setting before I took it apart.
Any Carter YF Experts out there?
