Not a Kawi but when I rebuilt my Triumph engine it spun and spun with not even a cough. When I put my hand over one of the carb throats there was no suction at all. It turns out we had miscalculated the cam timing (no timing marks on custom cams). Once we redid the cam timing it started as soon as we touched the key. Live and learn.
Jim
North GA
2016 Yamaha FJR1300ES
1982 GPz750 R1
1974 Kawasaki H1
1976 Kawasaki KZ400
1979 Yamaha XS650 cafe'
2001 KZ1000P
2001 Yamaha YZ426
1981 Honda XR200 stroked in an '89 CR125 chassis
1965 Mustang
1967 Triumph GT6
1976 Bronco
"If you didn't build it, it's not really yours"