On my 84 vf1000f fueled it up for the first time today and when i went to restart after fillup it really struggled to start.waited about 10 min. and then it started,what should the cca be on the battery?I have a digital midtronics battery tester so i will ck it tommaro at work.if the battery tests good will a bad starter relay cause that?seems to crank slower when hot but also kinda slow when cold too.dont know how old the battery is but the bike was sitting a while without being driven.
You will also want to take a look at the brush area in the starter. If the brushes are still good, then take some crocus cloth to the commutator and clean it up. Both my 1000f and 1000r had the same symptoms, cleaning the commutator on both fixed it right up.