Volvo AQ145A Engine stalls.

Hi everyone im in need of some help please with a problem i have with my one of the volvo penta aq145a engines, when i fire it up it will run for 10 minuets and then die. after about 30 minuets it will start again i have replaced the coil,rotor,dist cap,points and condenser set the point and the dwell angle to the correct setting in the workshop manual.and it is still playing up if anyone could help at all with pointing me in a direction for a possible fix i would be very gratefull.

Nige