Re- your cold starting issues
What carbs are fitted ?- if they are Hitachi SU type then no amount of pumping the peddle will help as they have no accelerator pump, the carbs rely on manifold vacuum to draw fuel and air into the cylinder......you need to use the choke which pulls the primary jet down and enritchens the mixture- if fitted then it probably needs adjustment - If not fitted then you may need to refit one to solve the problem.
If you have triples fitted then your accelerator pumps need looking at .
How is the warm start ?
cheers
Al.