No spark

[big albig]

my mate has just phoned me who has got a R1000RT 1981 but has an intermitant spark problem, Somtimes the bike will start no problems, other times it won't and when he checks for spark there is none on both cylinders
he has done the earth check's and all seems to be fine, and a new battery was fitted because the bike has been standing for a few years, any suggestions please.

Thanks
Alun on behalf of Dick.