Use some Devcon Epoxy Steel, after you've beadblasted the pulley and thoroughly cleaned all the glass beads away. I use massive amounts of high-pressure air through a needle-tip blow gun to make sure there's no residue of glass beads in the pitted spots. If any are left, they act like tiny ball bearings and keep the filler from getting a grip. Follow the mixing and application directions to the letter. Epoxy steel is like J-B Weld on steroids.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!