proper height

[Nason]

What is the proper height to run a chopper below the pad( center of prop shaft to bottom of pad)?

I am running now 3.5 inches from bottom of pad to center of prop shaft wit a 10.25 x 18p chopper,turning 5800rpms. If I try to come up to 3 inches below pad it just blows out. Do you think a larger dia prop would be better?

[Mark75H]

on what boat?

[Nason]

its a home made 14' semi V aluminium hull with a 14" pad (weight of hull withhydraulic jack plate 450,motor 204 )

[Nason]

[Nason]

[Nason]