Honda Spree and Elite 50 Forums

If your carburetor was loose from the intake, that would definitely cause air leaks. Lean conditions would cause the engine to run hot and you may have seized your top end.

Also, before peeling the decals and painting it might be worth it to try a $10 can of Maxima SC1:

I know you said the seat is still in good shape, but they have replacement Spree Special covers on eBay