Does the 2002 R1 clock have a fuel gauge?
Does it have all the warning lamps needed for a BEC?
Do I need yo buy more stuff to go with it?

Don't know about the R1, but any dash using bike clocks will need at least a brake fluid warning light. Possibly a fog light warning light (if your chosen switch doesn't light up) and a hazard swich / warning light.

Hope that helps.

Mike

It has a fuel level warning light if you use the submerged bike pump, but not a gauge.
It also wont have oil temperature / pressure readings which is something I think is good to have, especially on track.

As Mike says youll also need some of the lighting tell tales like fog and hazards but usually you just buy switches with integral warning lights built into these. The rest of the tell tales (main beam, indicators etc should be re-useable from the bike dash.