my '91 zxr750 j1 has died a death - from working ok (minus the fact she hasnt idled for 18 monthd

now ive had everything off - cant see any changes to the carbs from last time they were off - although they do need sorting properly.
i checked the plugs - c1+4 were clack and 2+3 were white.
also there doesnt seem to be a strong spark when turned over and allowed to spark on the frame...
can anyone point me in the right direction?
its landed the worst time ever - 3 days after splitting up with my wife...

cheers all....