1998 and up z50s have a cdi. Every z before has point ignition.

 

Are you sure about that? My 93's wiring is clearly different than my '85.

 

I think its more like 88 and up not positive on that though

 

Looks like DrATV added some new pages on their site. Here's the final word I guess:

Z50'S

SAME BASIC ENGINE 1968 THRU 1981

IN 1982 CHANGED OIL PUMPS, TRANNY CASES, HEAD AND CAM, CONNECTING ROD, PISTON

IN 1988 CHANGED FROM POINTS TO CDI IGNITION

IN 1992 CHANGED CAM AND HEAD, PISTON

 

an old xl or ct heads are the best for the money they were for bikes on the street had lil bit bigger valves and bigger ports atc 90 intake compliments it too