We took the carb off today and cleaned it out. The jets seemed pretty clean, but we blew them out with compressed air and sprayed them with carb cleaner. It seemed to run well; we drove it around town for 20 minutes or so, and it didn't die at all. (Our shorter test drive when we bought it had it die a few times in similar driving, but we've since fixed a leaky connection at the fuel filter.) It still idles way too high, though; it usually idled at 2500-3000 rpms, except for a little while when it idled roughly at 1000 rpms.
We really think the engine has been worked over by somebody who knows less about working on cars than we do.
We noticed that the gasket on the choke bimetal spring housing was missing; the choke would rotate freely with vibration or force on the hoses. I cut a new gasket out of cork (it's just there for mechanical friction, not sealing). The choke hot water housing backing plate was also installed rotated wrong with only 2 of the 3 screws lined up.
Also, the 'power valve cover' and 'bowl vent valve rod' weren't connected properly. The bowl vent valve rod was just wedged against the bottom of the carb, not connected to anything, and the power valve cover was only held on by the vacuum hose that was in the center hole. When we disconnected the vacuum line, we lost the 'power valve cover' and 'bowl vent valve rod'.
We also had fuel being pumped out of the vacuum accelerator pump cover when we took off the carb. That concerns us, as that barb should have been connected to vacuum, so there shouldn't have been any fuel in there. However, after we disconnected all the hoses and were manually actuating the linkages, actuating the throttle caused that barb to spray fuel the first few times. When we opened it up, the chamber that should have been the vacuum side was wet with fuel, but the diaphragm didn't look horrible.
Considering that, I'm surprised it runs as well as it does.
Tomorrow, we're heading back down to take it for a test drive on the highways; when we bought it, it started having major issues within 15 miles, so we'll take it about twice that. If it handles that well, we'll drive it up to Minneapolis so we can keep it in my garage for easy access.
