Rob,
Re the cable issue; you might want to double-check if the brake pedal pivot has been bent slightly. My buddy dropped his MT250 at, like, 1 mph, and all
sorts of stuff got mangled, including the pedal pivot mount. It's also possible the kickstarter is too far in on the shaft, or the cable clevis (U bracket) pivot pin has backed out after losing its cotter pin.
The brake switch spring is (discontinued) Honda P/N 35357-358-000. Here's a link to a place that apparently has 3 in stock:
http://www.hondarestoration.com/nosResu ... Sport-1976Another link to the shop manual, right here at VDB:
http://www.alp-sys.com/honda-elsinore/m ... 5mt250.pdfCheck out page 31 (it's actually the 33rd page of the .pdf file), and I believe there are other photos in there that might help too. It looks to me like the spring runs straight from the clevis to the switch.
Ray