plugs on prop

[BIG PAPA]

What do the rubber plugs on the prop do?

[BassBUFF]

They are there to allow adjustment of how much exhaust is applied to the blades for slippage.

Examples;

Problem: Motor lugs out of the hole, won't spin up. Fix: change the plugs out to a different size opening to allow more exhaust over the blades to increase initial slippage. This allows the motor to rev up faster.

Problem: Motor spins too high on holeshot, redlines. Fix: Change the plugs out to a smaller size opening (or completely plug some) to allow less exhaust over the blades. This decreases slippage keeping the motor from redlining.

These examples are two extremes. You can swap plug configuration around to fine tune the prop to the boat/motor combination. Hope this helps explain it .

[BIG PAPA]

Perfectly Steve, thanks!
Kind of what I thought but really did not understand till now.