I picked up another Express today. an '81. Got it at the scrapyard for $35.09.
Cylinder is scarred up to the point that it wouldn't run from lack of compression.
Soon as my wallet recovers a little from the BMXpress this one gets an Athena kit (I'm hooked, it's worth the $$) and a proma (it's cheap and rips hard). I have an idea that I think will let me make 2 cuts on the proma, twist and reweld so that the bend at the fat part of the chamber wraps around and over the flywheel cover, putting the stinger parallel to, and about ten inches above it's current position. I think it will look cool and not rob so much ground clearance. I'll post pics once I get to it. Fuel tank is definitely going to be the bucket under the seat for this one, and I plan to make a seat pan that fits the bucket and doesn't overhang 2"all the way around it.
I never woulda thought I'd end up hooked on mopeds. Nothing against them I'd just never given them thought. They are an awful lot of fun for not so much money. I have a dozen other projects running through my head already. Already bought a Jesse James Bicycle for a donor frame (250cc two stroke coming up :)). When I get hooked on something I go full bore for awhile...