cbr900 fireblade not cold starting
 

hi all ive got an HONDA CBR900RR 1995/1996 model .
first a bit off history on the bike.
the bike was rebuild completely from 2 bikes as it was in a major accident about 3 years back
engine was repacked with new bearing and oil rings(no valve stem seals tough)
rebuild took about 3 months got it up and runing but ran in to some problems since so took it to a bike dealer to sort it out on the dyno ,
he then replaced the following spark plugs,pickup,carbs,module inside the rpm counter after a bit of tuning the bike ran great for about 2 weeks
then suddenly i picked up an issue with starting if the bike was standing for about 2-3 hours i have to bump start it and it takes a while trying to get it started
i have tried jump starting on a proper booster starter swings over but does not start at all
i have since changed spark plugs cleaned out the carbs again but still no improvement
any idea on what can cause this your advise will be appreciated thank you in advance

Have you checked the rubber Insulators from the carbs to the engine make sure their screwed down tight as they could be destroying the vacuum, I see you've had the carbs off a couple of times, also check the vacuum pipes are clear at the tank

does anybody maybe know the correct air/fuel mixture screw setting for the bladefound that they were not set equal on any of them

Should be 2 to 2 1/2 turns out