Well bugger, I busted a backplate.
It had to happen sooner or later I guess. I'd been flying my pee wee powered roaring 20 around having a grand old giggle when after fitting a new reed in it the engine would run for about 30 seconds and die. I got tired of that kind of malarkey and hung the plane up for a while.
I finally got around to looking at the engine, and sure enough, when I pressurised the tank, one of the bottom screw recesses was leaking. I opened it back up and the pot metal has split as the pot metal backplates are wont to do.
Is there any way to fix this? Cox international doesn't have any 020 backplates, so am I screwed?