That's a pretty common problem with 216 balancers- - - -unless you're using a puller with a pretty small diameter jackscrew, the push force isn't getting to the crankshaft snout. Use a socket like Tiny suggests, or a piece of round stock that will fit through the center hole with a dimple drilled into it to center the puller cone. The puller is working against itself if the cone can't touch the end of the crank.
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!