jetting issues

[87shee.cny]

new to site ,have 87 shee bored 40 over fmf pipes boysen rad valves and kn filter ,run open air box 280 main jets and 32.5 pilots have had carbs apart and cleaned several times has a weird hestation at like quarter throttle ..... and yes i have syncd the carbs any ideas ????? 

[fastbanshee8]

Pilot jets are too big.  Try some 27.5's, and some 30's.  Adjust air screws as needed.

[sleeper06]

Where are you located