I got the oil filler plug/dipstick out tonight. Recall that I said I broke the handle part; as I noted elsewhere, my plan to remove it was to Dremel a slot in the top, then use a large screwdriver (one of those that you can apply a half-inch wrench to for leverage) to remove it.
Short version: Slot yes, remove with screwdriver no. I still couldn’t budge it.
So I decided to use the Dremel to cut a notch out of one side, then used a cold chisel and hammer rather gingerly to loosen it. Somewhere along there I applied heat, and I used a bunch of PB besides. Finally, it broke loose and came out.
Amazingly, I’m pretty sure I didn’t get any shavings into the crankcase. I threaded the plug back in a couple of turns to keep crud out of the engine, and moved on to that troublesome frame hole with the broken screw in it.
I had a brand-new “easy out” of the sort that can be turned in either direction; it was my hope to turn the stub of the bolt in rather than out, as I am pretty sure that rust on the end of the bolt is what caused it to jam up and break in the first place. But no luck… it won’t move, and I’m pretty sure now that I’ve screwed up about half the female thread to boot… the easy-out just kept taking shavings out of the bolt rather than moving it.
The hole that is troubling me is the left-hand (i.e. front) tool tray bolt. Since the tool tray seems to also be the retainer for the battery, I’ll have to do something about it. I think I can just cut that threaded bit off the back, then use an ordinary nut in place of it; it’s not hard to get a hand on it from the front with the carburetor housing off.
I pulled the horn and opened it up, and it looks pretty clean inside; there were some cobwebs in the horn opening, which I fished out with a piece of wire. But it still sounds like a sick cow when I honk it with a fresh battery. Not sure if it’s supposed to sound like that or not.
Anyway, I made some progress. But the pistons are still stuck. I’m going to try the acetone-and-ATF cocktail just as soon as I can get some acetone.