prop size

[kohouty]

hey guys i have a 73 v20 with a 165 i/o

what is the best prop for speed. I have a trolling motor, so i just want to get out there faster.

I have a 17 now, I get 32 mph at 3800 wide open.

please help
thx
Chris

[Destroyer]

Hard to say. What is the horsepower of your engine and what is the factory recommended WOT RPM for your engine? It's nice to go fast, but it's more important that you don't destroy your engine by overloading it.
You want to match your prop to whatever is recommended. For efficient performance, it's critical that your engine operates within the RPM range recommended by the manufacturer. Matching the right prop for the load is the most significant factor of RPM adjustment.

Generally speaking, a pitch change can increase or decrease your RPM's and bring RPM's into the recommended range. A 2" increase in pitch (for example, from 17" to 19") typically results in a decrease of approximately 300-400 RPM.

You should be looking for a 15 tooth spline, thru-hub exhaust prop and your prop diameter can vary from 14 1/4 to 15 1/4". :beer:

[RidgeRunner]

Sounds like the 17 is too much prop. If you overprop you loose speed and kill the motor as Destroyer said. I think the 165 was made to tach out at 4600 wot. I would try a 15 and see what happens.

[Blue_Runner]

What they said..........

Unfortunately for you going down to a 15 pitch prop is going to detract from your top end. How is the hole shot? Does she come up pretty quick or a little sluggish when loaded?

[spareparts]

15 may help with top end as well, it allows your motor to reach an rpm where it makes more power than at 3800, look for a big ear 15(flat blades), they used to work pretty good with the straight 6 motors