Stingray actually increased speed....

[ozarkt165]

Installed series II stingray hydrofoil on 70 horse johnson. Increased top speed w/ passengers from 26 mph to 32 mph. Solo top speed of 34 mph did not change. Figured if it increased speed w more weight it would go faster solo. Guess it is time to prop it.

 

[Bifflefan]

Re: Stingray actually increased speed....

That sounds just about right to me.
The foil will get you farther out of the water with a load, but solo you are already out as far as you can be.

 

[CharlieB]

Re: Stingray actually increased speed....

First and most important thing in selecting a prop is your WOT RPM.

Without an accurate RPM you risk either over-reving or over-loading your motor and causing serious damage to it.

Post your info in the Prop Forum and the guys there can help you decide how best to proceed.

 

[ondarvr]

Re: Stingray actually increased speed....

Did you raise the motor up higher on the transom?

 

[ozarkt165]

Re: Stingray actually increased speed....

No did not raise motor, cavatation plate is within a few inches of bottom transom. Good enough for me

 

[CharlieB]

Re: Stingray actually increased speed....

The reason the poster asked the question about the A/V plate is that if the plate is LOWER than the boat bottom then more of the gearcase is exposed to the water flow and creating excessive drag, effectively reducing top speed.

Generally, dead even with the bottom will give good performance and handling.

If the motor is set back from the transom, using some sort of 'jacking plate', then the motor may be able to be raised further.

 

[5150abf]

Re: Stingray actually increased speed....

Get the engine up as far as you can without cavitating, even one hole up can make a huge difference in speed, the less you have dragging in the water the faster the boat will go, not many chances for free speed on a boat.

 

[bob johnson]

Re: Stingray actually increased speed....

No did not raise motor, cavatation plate is within a few inches of bottom transom. Good enough for me

a few inches!!!!!!!!!!!!!!!!!

ha ha ha

bob

 

[ozarkt165]

Re: Stingray actually increased speed....

Okay 1 1/4 below. LOL Stingray is out of the water WOT

 

[ozarkt165]

Re: Stingray actually increased speed....

When trimmed up on plane of course.