Tuned the ignition and carb. Set the motor tester up, got the dwell in-spec at 61 degrees (59-67 is the spec, I started at 52). Still stumbling a lot under load, and I found if I put the choke into it, it picked right up. I riched the mixture but ran out of adjustment and it still wanted more.
At this point I figured there must be something wrong with the carb. Ignition and timing were both fine and the motor is internally healthy.
I tore the carb down and checked everything against the Greenbook, and reset all the adjustments to the initial values.
I found the needle seat was recessed 2.79mm, the spec calls for 3.0mm +/- 0.2mm, so I tweaked it a few times and got it at 3.07mm (it is not easy to make very fine adjustments to the seat, it tends to either not move at all, or move too far, so it takes some patience overshooting one way then the other, until it lands where you want it to).
I still haven't done final adjustments with the CO meter, but Buttercup now makes great power. The base timing is at 12 degrees, I'd like to move it closer to 20, but I have to pull the distributor out and move it one tooth to do this (!) this is due to a really random problem - the vacuum canister on the dizzy interferes with the power steering pump bracket. So in the "correct" position the lowest I can adjust it is 20 degrees BTDC, and in the "one tooth retarded" position, the highest I can adjust it is 12 degrees BTDC. So I will have to... I dunno, exactly. I'll figure something out.
