I'm getting a new tiller boat at the end of the month and it has a 2011 Mercury Four Stroke on it with the Big Tiller handle but doesn't have the RPM Adjuster on the handle. Two questions with regards to this:

1. To add the RPM Adjuster to the handle do I just need to purchase the control, Merc. p/n 897978T01, or are there any other additions required as well? Looks like about an $80 part. If so, is it something I could install myself?

2. Will having the RPM Adjuster allow me to actually troll down slower? Or will it just allow for greater adjustability? So what I'm asking is will my slowest speed with the RPM adjuster be slower than without it and just turning the handle as slow as it will go? If there is a difference, how much?

Thanks in advance!

Joe

I've been told by folks at Mercury that the Troll Control switch can be easily added to the handle, so I'm guessing it's a DIY job.
As far as rpm ranges, below is a chart I've got, that shows the normal idle rpms, and which motors can go lower. Looks like your 90 4S can be dropped from 700 to 550.
HRG

Your just need to find the wires, and plug it in. Easy enough, if your lucky to find the wires quickly.

Most motors the troll control allows specific control setting the troll speed up, but on some it does lower the idle speed. HRG found the chart to show that.

It's worth it to gain precise control on rpm in the lower range. Takes a bit to get used to it and not bump the throttle which results in disengaging the troll control.

Thanks for the info. I might as well add the Adjuster since it's only $80, no point in not having all the available features of the handle. So what will going from 700 to 550rpm's get me as far as speed reduction? Say going forward on a calm day? The boat is an 1825 Pro Guide.

Joe

I just put one of these on last night, so I'm going to change my statement about finding the wires.

First - the instructions that come with the troll control idle switch explain the process completely, and very clearly. Simple job.

There's a plug-in inside the handle that the 4 wires for the troll control will plug into. You'll have to remove the large plastic piece on the bottom of your tiller handle to access.

The diagram explains which hole each wire goes into. If the wire does not push in easily until it clicks into the holder, rotate the connector 180 degrees, there is a very small difference in the spade that has a retainer on one side, but not the other. If your pulling, pushing hard, you've got it turned the wrong way.

You'll need a small standard screw driver, a phillips screw driver, and a needle nose plier.

It's a 15 minute job, start to finish, maybe less.

I'm sure it will be much easier for you if you get the right wire in the right position the first time, so take you time and read the instructions.

remove duplicate post

Thanks for the info. I might as well add the Adjuster since it's only $80, no point in not having all the available features of the handle. So what will going from 700 to 550rpm's get me as far as speed reduction? Say going forward on a calm day? The boat is an 1825 Pro Guide.

Joe

Joe, I would just have your dealer instal the Adjuster. I am sure for a new boat they would do this at no charge. I have the 1825 ProGuide with a 90hp Yamaha 4st. I can get my boat down to 1-1.5 mph going forward on flat calm water. With a little wind it will get down even slower. Love the option as Burr stated about. Great for precise boat speed control.IMHO

x2 stinkycat