Well the Champ hasn't been running since the Veteran's Day Parade. I got home and the starter would not engage so wound up pushing it off the trailer and into the shop and there it sat. A couple of times I've been out to try and diagnose the problem and couldn't come up with anything. I always checked the batteries, individually and combined, and they always showed fully charged but when I hit the starter switch - nothing. It's a little difficult to run a multimeter on the wiring in the engine compartment when you have to activate the starter switch on the dash all by yourself so I was stumped.
Yesterday keith_j came out and we spent about 2 hours fiddling with it. Once again, of course, checked the batteries and while one was slightly down they were still in good shape. We started at switch on the dash, went through the wiring from the switch to the starter, then through the wiring to the ballast resistor, each time checking the batteries. Finally we were about to give up when Keith decided to check the batteries while I tried starting it. Suddenly we had 1 go from 12.8v to around 6v. As soon as the load was dropped it bounced back to 12.8v. So every time I checked it in a static state it looked fine but under load it crapped out.
We swapped that battery out and the Champ fired up like it was brand new with no choke and very little throttle.
I'm sure some of you reading this are going "well, duh! I would have known that." I didn't and if Keith did, he didn't think of it. Of course it'll never happen to me again or if it does my CRS will have kicked in so I won't remember it. At least now it's running so on to something else.