I've got one. I spent a lot of money and time refurbishing and improving the chassis, only for the engine to let go in a big way. Has anyone got a decent engine for one of these? Better still, does anyone know if a GPX/GPZ750R engine will fit? If so, anyone got one of these?

Is it not time to bite the bullet and upgrade the bike as a whole? ZX6R's can be got cheaply now, and they are faster, better handling and you don't have the aggro of fitting a new engine/matching wiring etc....:)