crank but no start

[WICHOL98]

im trying to get my cb750 started but it wont spark

[Leerider]

Get 2 ~6V~BAT~MAKES~12V !  HA CRANK & START HA ! 12V !  ~U~D@ THE MATH

[81cb750]

I just picked up an 81 CB750. I found that the bike would turn over but would not fire unless the battery was pretty strong. Originally I figured it wqs turning over fast enough to fire, but decided to go ahead and put the battery on a trickle charger over night. Fired right up! This was after a rebuild on the carbs.

[WICHOL98]

i got it started this weekend but the piston closes to the master cilinder wont fire at all