fzr400 start problems

my fzr400rr 3tj just wont start. the starter motor turns but their is no spark. i can bump it 'just' and it will start on the motor when warm.

also when reving, it somtimes limits at 4000rpm for about a minute and cuts out when i pull the clutch in, (rarely).

ive cleaned all connections, carbs and spark plugs with no change,

could this be a faulty CDI unit or is it a different problem.

if CDI, where is this on the bike.

cheers