I think the recommended break-in prop is a 16/8 so it will crank that 16/4 with no troubles at all. I broke my Saito 100 in with the 16/8, 5 tanks on the stand and 6 flights both at rich settings, then adjusted the valves, leaned it out some and switched to the 16/6 just to slow my P51 down for landing purposes only. Purrs like a kitten!