Tell me what I did wrong...

I have been shopping for a boat for a few months. 

Finally, I inked a deal on a Alumacraft 165 tiller with a 50hp Evinrude sitting on a roller trailer. 

The only fear I have is...  the motor is so big that I will not be able to troll with it, because it will just push the boat too fast,  even at a idle. 

I need to buy a bow mount electric and a new sonar unit for the back if you have any suggestions

5 gallon buckets work great,add a second rope to bottom of bucket to make retrieval easier.Idling for long periods probably won't really affect an E-TEC,but can be a problem for 4-stroke outboards(fuel/oil dilution).Much more so in cold weather,unless you have a hotter thermostat. 

I'd have to ask my wife . She does it for me constantly  !

Nobody has mentioned back trolling. Everyone wants you to spend more money and add a bunch of heavy and expensive electronics. My old boss dropped a couple of plastic buckets on ropes over the sides of his boat.

Naw, you did nothing wrong.  All you need is a good bow mount trolling motor in front.  Get an Ulterra, link it with a good Humminbird graph.  Now you can stow and deploy with a push of a button.  Get a 24 volt system.  If you want to go .5 to probably 2.8 or 3.0 that trolling motor will be perfect.  And...if you want to troll with the big motor, simply turn the head on the trolling motor towards you to slow it down some.

The motor has Touch troll on the tiller. You can lower the idle rpm. It will shake the boat more when you slow the engine. Give it a try. 

nice boat...congrats on your purchase.  I have an 18` tiller with a 90hp merc... I throw out a drift sock and can troll down to 1.7mph no problem....maybe slower  but havent tried. A  far as trolling motor and graphs....just do your research and get what your price range allows.  Lowrance and Humminbirds are both great units, just learn all the features they offer.... the best advice I can offer on graphs is get the biggest screen you can afford.  With trolling motors...Motorguide and Minn Kotas are both excellent

You could also pull a trolling bag!

If I troll, I just use the trolling motor.  The new trolling motors are easy on the 24V battery set-up I have.  I like the control better from the front vs the back.  Locator and trolling motor-wise, I'm a Bird/Kota guy, but I'm sure the Lowrance and Garmin units are fine.  Kinda depends on your budget.  The side scan is a pretty useful tool for me.  The rig looks sweet, enjoy. 

You could always get a trolling plate...

I have a 17' Princecraft with a Evinrude 90 e-tec, at idle it goes about 2.8-2.9 mph.

First,  I don't think you did anything wrong.  Nice rig!   I am curious about how slow you could expect to troll with your motor?  I have a 16.5 foot D Star (side counsel ) with 50 hp yamaha.   I can troll down to about 2.1 mph at idle.  Is that slow enough for your needs?  My front trolling motor allows me to troll any speed slower or up to 5 mph.  When you get your front troll motor i think you will be good to go.  I do recommend getting I pilot with spot lock.  Game changer.

Good fishing!  Shellfish

I had a 165 Classic 165 with a F60 tiller. I could troll all day with that engine. I would add a Minnkota Terrova 24V, 54” shaft to the bow. You will be able to handle most conditions within reason.

I now have a Escape 145 with a 30HP ETec tiller. Mine has the variable idle button which helps with trolling. 

You have a very nice rig!

Thats a nice rig. I used to have a tiller, but as I get older, i ordered my recent boat with a console, I'm going for comfort now.

Did nothing wrong. Great setup. Enjoy

Looks like a great setup. Tiller is a smart choice giving you lots of room. 

Mine. I took out all seats but the one on front deck. Put my electric troll motor on right rear this allows for quiet approach to fishing spot.