Questions about trolling with "big" motor

[tmcaul]

I have seen a number of threads from guys trolling with their large hp four stroke motors. My new boat (2017 Lund Tyee 1800) will have a 115hp Mercury four stroke and I intend to start out trolling with that motor.

My first question is whether I can run all these electronics on the single cranking battery that is currently in the boat: boat instrumentation, fishfinder, Fish Hawk (eventually), bilge and livewell pumps, and two downriggers. Will the Merc's alternator throw off enough voltage while trolling to power everything? Or do I need to add another (deep cycle) battery? I would estimate that I would run the motor at power for maybe 30-40 minutes each time I go out (to get me to where I will fish and then back home).

A second question is whether I will be able to use the throttle control to maintain trolling speed? Or do I need to add to next winter's budget the Mercury Troll Control.

Last question: Will I need bags to lower the boat speed to 2.2-2.8 mph? I recall Digitroll ran at least one bag some of the time with his 150hp Merc.

All of my fishing to date on Lake Champlain has been with two motors, main and kicker. But I'd like to just use the 115 that is on the boat if I can. The transom design on the Tyee makes it easy to add a kicker.

Thanks for any advice.

Tom

[C-Hawk]

I have been trolling with my 2014 115 Merc 4 for 6 seasons on the same battery. If it starts at the dock, I'm good to go. One time after a trip up in 20° weather, it would not start although it turned over fine. I went to the Marina and they boosted the battery, and it fired. Evidently , it takes 10.5 volts to make a spark, something to be aware of. Never have to worry about running too much electrical equipment as the automotive type 65 amp alternator makes plenty of juice.
My Islander trolls down to 1.8 without bags, and you may be able too, but the bags are way less of a headache than the kicker.
I think the troll control is the only way to go. I can get less rpm than my hand controls are adjusted for. However, there is an upper limit at 1000 rpm which I wish could be higher for windy conditions.

[dry net]

I have an 18ft lund with a 115 on it. Way to fast to troll without bags or equivalent. Thats why there's a 9.9 kicker next to it. One battery does it all on the boat. My main doesn't have the ability to add a troll control though. Good luck, Matt

[C-Hawk]

I have an 18ft lund with a 115 on it. Way to fast to troll without bags or equivalent. Thats why there's a 9.9 kicker next to it. One battery does it all on the boat. My main doesn't have the ability to add a troll control though. Good luck, Matt

is your 115 a four stroke?

[Dirtyhooker]

I ran a 135 Honda on 18 ‘ triumph center console 3000 hrs never a problem 1 battery for all needs other than bow mount minnkota I could get down to 1.8-2.0 mph on depthraider or 2.2-2.5 on Fishhawk most days the digital throttle control would be the way to go though bags are not really a bad deal as I use them on my current boat even though I have a kicker when it gets rough far better boat control with big motor than kicker

[Reelax]

Tom... you are lucky. That motor is
One of the best big motor trollers out there. I got over 1000 hrs on mine and it runs like new.

Use a troll controll to have digital push button control of 10pm adjustments down to 550rpm.., install yourself for $550...

My 90hp merc uses a
27 series dual use high end battery that has run all my electronics and power down riggers for 5 years with NO problems.. no need for 2!

580rpm will push that boat at 2mph if I guess right! Perfect

No need for bags if you do it right.


You are well on your way... nice choice in trolling platform!

[dry net]

I have an 18ft lund with a 115 on it. Way to fast to troll without bags or equivalent. Thats why there's a 9.9 kicker next to it. One battery does it all on the boat. My main doesn't have the ability to add a troll control though. Good luck, Matt

is your 115 a four stroke?

yup

[keithm87]

I have a Yamy 115 on my 20ft Polar Kraft. Trolls to 1.6-1.7 with gear in, 2.2-2.3 with it out or early season (higher lighter gear). It is really amazing what rigger balls and mag divers do to increase drag. Prop pitch + RPM is your key factor. bigger or heavier boats will have a lower pitch prop, I run a 4 blade 15 pitch on mine for ease of planing, but lose a few MPH top end, but that gives me a really perfect troll speed. With the 19 pitch that came with the boat I was 2.5 or so and could barely get on plane, and the 17 I tried got me to 2.2, but couldnt get up with 2 skiers behind me. My RPM gauge doesnt work (most of my gauges dont haha). I would bet in a 18foot that Dry Net is running a 19-21 pitch prop. With a nice newer boat like the Tyee I would agree with Reelax that troll control is a good investment. Kickers get in the way (though they do give a way home if something goes wrong)