Trolling with Mercury 2 stroke 115 HP on my Astro fish and ski

[darkhorse91]

I bought my Astro last year but I hardly got out with it. The dealer told me that I shouldn't troll with the 115. Other people say they troll all the time with two Strokes and never have problems. I tried trolling once last year and ended up getting towed. Shut it off to drift and it wouldn't start. Diagnosed faulty carb gasket. they changed them all. I welcome any advice from the forum. I fish on Lake Erie in the Central basin. Thanks

[Fins]

My 4 stroke 115hp Yamaha and my buddy's old 90hp 2 stroke Evinrude troll for hours on end in the fall. There's no reason a motor shouldn't be able to run at minimum throttle for as long as you like.

[06 SB]

If it is an inline 4cyl 115, it is a 2+2 motor. It idles on 2 of the 4 cylinders and then the other 2 come on line about 1800 RPM. Those can be problematic if idled all the time.

[darkhorse91]

Thanks for the reply. Yes it is an inline4. 2 of the cylinders cut out at low speed. I noticed this and asked the mechanic. What could get to replace this motor and keep the current controls? Any advice appreciated. Thanks for your help and also your military service!

[06 SB]

Any Mercury motor would use the same controls and go with the max rated HP too. I don’t think you need to spend that much money though. Personally, I would look at a MinnKota Ulterra or Terrova in the maximum thrust possible. With good batteries, it should last all day. Either has spot lock and depending on your GPS units, can follow preprogrammed routes or contour lines. They have remotes to control them no matter where you are on the boat. The only word of caution here is to make sure you do not use the cranking battery as a trolling motor battery. You want full juice on that thing to get you home.

When cleaned up and a proper link & sync completed, those 2+2 motors are reliable just an ancient design. If the fuel lines have not been updated, this needs to be done immediately. Old ones deteriorate with age and especially by ethanol in the fuel. Ethanol destroys the inner liner of the lines and gums up everything. Literally, every millimeter must be changed.

[darkhorse91]

Thanks again for the advice! I do have a Minn Kota 55 power drive V2 with dual deep cycle batteries. The starting battery is isolated. I stated boating 40 years ago. Like most boaters it was a 12' foot aluminum then a 14' then a 16'. Next was a 17' Silverline 27' SlickCraft 24.5 SeaRay sundancer. None of these boats had livewells, trolling motors. Bass boats are all new to me. My last boat was a new Bennington 20 pontoon. Great vessel. never got to fish just transported a bunch of big drinkers. got pulled over by marine police. I wasn't drinking that day but I was furious that the passengers wouldn't obey the law. Sold the boat that fall. Decided on a bassboat. it only seats two, just not familiar with this style of boat and the equipment. Another problem I have, can't see the boat backing up. Bought a pair of guides but they don't fit. Figured it would help backing up. Tow vehicle is a 2013 Ford Edge with 20" rims. Thanks for your help. Have a great Fathers day.