prop question

I just purchased a used boat. The motor has very good compression even
though it is an older motor. I ran the boat and it seems the top speed is
around 25 MPH. at 4500 RPM. I would like to increase this speed slightly.
Here is the boat specs:

Boat is homemade from a mold of a Boston Whaler hull. so hull is shaped
like a Whaler.
Hull Material is fiberglass
Length 17 foot

Motor is a 1984 Envinrude 70 HP with a 3 blade 13.25 X 17 prop.

My question is what size prop pitch should I try to go to achieve higher top
end.

Sarge

When you order a prop, call Michigan Wheel or whatever company and
ask what size prop you can use and what RPM and speed to expect.

Regards,
Cliff


Fishing: "a sport surrounded entirely by liars in old clothes"

licker wrote:

I just purchased a used boat. The motor has very good compression even
though it is an older motor. I ran the boat and it seems the top speed is
around 25 MPH. at 4500 RPM. I would like to increase this speed slightly.
Here is the boat specs:

That seams to be the right RPM's for a proper prop

Boat is homemade from a mold of a Boston Whaler hull. so hull is shaped
like a Whaler.
Hull Material is fiberglass
Length 17 foot

Motor is a 1984 Envinrude 70 HP with a 3 blade 13.25 X 17 prop.

My question is what size prop pitch should I try to go to achieve higher top
end.

I think motor position (tilt) might increase this more than a prop
change. Your running a very heavy boat for a 70


--
Rodney Long,
Inventor of the Boomerang Fishing Pro. , Straight Up Hooks ,
Straight Up Lures, Mojo's Rock Hopper & Rig Saver weights,
and the EZKnot http://www.ezknot.com