Help with prop/idle speed?

[Troutdoc]

2004 Palm Beach 17.5, 2004 Evinrude E-tech (168 hours)
​Prop stock 13.75---15
Boat runs 3.0 mph in gear at idle...at 800 rpm.
Dealer says cannot lower idle speed.
I need trolling speed at idle to be 1.6---1.8 mph for brown trout/rainbow with downriggers
Do not want to buy kicker motor.
Other than trolling plate and or buckets----if I change the prop pitch to 13 or lower, should this lower the speed to what I need?
Thanks
Troutdoc

 

[Seahawk170]

Not sure about trolling that slow, but a little 3 or 4hp kicker motor would sure do it. There's also a trolling bracket that can be added to the anti-cavitation plate which flips down to divert the prop's thrust, and flips up for cruising.

 

[fhhuber]

Drag a couple of 5 gallon buckets on ropes.
Cheapest and quickest solution.

Lower pitch will slow you down a bit... you want half the speed... you need half the pitch. That means half the top end speed....

 

[steelespike]

What is the hp?This problem pops up every once in awhile.The prop change is usually not effective.
in my mind a trolling plate is the most effective without sacrificing other characteristics.You could try trimming way up but will be difficult to control.

 

[steelespike]

Assuming the motor is a inline 75 or 90hp a 9" prop at 800 rpm and 40% slip would make about 2 mph.
Then if you run at 5500 rpm and 12% slip speed would be about 20.You would have to watch the rpm very closely.

 

[H20Rat]

Yeah, you said it, but buy a kicker... Big engines don't like idling with a load, lots of wear and possible overheat. A kicker will also give you much more fine grained speed control (you did say 1.6 to 1.8 mph!), and also some redundancy if the big engine quits.