Late bus stuck accelerator

Bloody accelerator pedal won't return when pressed on the '75 bus.. I'm a bit mechanically challenged, any clues as to the cause and remedy would be greatly appreciated.
Cheers

[ Edited on 30-4-06 by soft notch ]

Return spring on carby off
Cable freyed and stuck
If twin carby, maybe throttle linkage has dropped off and jammed

The start of looking would be at the engine end, and seeing if any springs or linkages are off, jammed or sticking.

Cheers