2010 Bennington 2550 RCL ESP

[Dahl]

I have just installed an E-TEC 300 G1 and need some help finding the correct prop.

Today with a full load of fuel myself and 300lbs of gearI was only able to hit 39mph on GPS @ 5600 trimmed out. Pontoons are clean - not polished.

Current prop is a Rebel SS 15x15 3 Blade

Lake elevation is 2300'

"Feels" like it slips a lot.

Old motor was an E-TEC 150xl 13 pitch x15 and would hit 29mph loaded down with everything including the kitchen sink.

Thanks!

Steve

[ken2]

Using the speed calculator. (its normally within 1 mph of what actually happens)
http://www.go-fast.com/boat_speed_predictions.htm
lets say 4000 lbs, 150 HP, 29 MPH gives a hull factor of 150.
Now put 300 HP in there and calculate the speed and it gives 41 MPH.

So your not too far off.

Here is an F300 Yamaha on the same boat with 1/2 tank of fuel, nothing else, at sea level, on a 49 degree day. (not going to get much better numbers then that)
They cost 46.8 MPH http://yamahaoutboards.com/sites/def...-05-04_pnt.pdf


So your at 5600 RPM with a 15 pitch, running 39 MPH. your at 9% slip, which isn't bad.
Couple choices, you could have a little cup added to that prop which would help if the prop feels like its breaking loose in turns or rough water to easily.
Might even pick up 1 or 2 MPH.

Or if you want to go for a little faster speed, I'd like to see what a 17 pitch Mercury Enertia or Quicksilver Q3 would do.
They normally cruise well, and they are fast.

[Dahl]

Hi Ken

Thanks for the reply. Today I am out at the lake and brought two props with me. Here are the "results"

15x15 Rebel - 38mph @ 5500rpm trimmed - "feels" like it slipps and the corners are "loose"

15x15 - 4 Turning Point Express - 38mph @ 5500rpm trimmed - grabs hard and pulls hard in the corners (best of the three)

15x17 - 3 Turning Point Express - 31mph @ 5700rpm can't trim up at all or it looses traction - terrible acceleration compared to the other two.

is it just me or is this a bit strange?

Thanks
Steve

[ken2]

For some reason, that 3 blade turning point is slipping horribly. It happens.

So your stuck at 38-39 MPH.

I'd try a 17 pitch Mercury Enertia and see if you can gain a little speed.