[update: Merc is now releasing a new product that will make the below unnecessary if you are running a NMEA 2000 chartplotter/gps and smartcraft..see here:
http://www.veradoclub.com/smf/index.php?topic=2403.0*****************************************************************************************************
The way your boat comes it reads speed for the speedo using a "notch" in the front lower leg of the engine. That's called the "pitot" and it's pure crap. It is inaccurate so therefore it gives you bad MPG and gets clogged with seaweed. Further , when it clogs, it will give you an alarm called "check Pitot" which is impossible to fix unless you are on the hard or want to jump overboard. . I pulled this from the owner's tips as this is the first thing you should do if you have the smartcrft speedo and a good GPS.
From the owner's tips in the Library:
Hooking up your Smartcraft speedo/SC 5000 systemview/vesselview to use GPS instead of the unreliable
pitot tube. Never get a “check pitot” alarm again...
A lot of new owners don’t realize the speedo is digital and can take NMEA output from your chart plotter/GPS to read speed, time and GPS info. Coming out of the back of your GPS are usually two wires called "NMEA out" (TX+ ans TX-) . The wire labeled “ TX+" should be connected to the white wire/blue stripe of the speedo. The other wire coming out of the speedo is blue/white stripe and should go to the same ground used to power the gps.. Now go to the "CAL2" setup of the speedo (see smartcraft PDF file in the library) and you will be able to choose "GPS" for speed which turns off the pitot tube. . If this does not work, just reverse the wires - and yes, that's in the install manual from Merc....NMEA uses small current so you can't blow anything up...You GPS also will need to be adjusted under the settings menu to send NMEA siganals out thru the wires --if you can set NMEA sentances, it needs RMB & RMC - see your owner's manual for that. If there is a "baud" setting for the data, the setting the speedo likes is 4800 baud. Note: If you have vesselview and a SC1000 speedo - you will have to feed both. Now tuen everything off and fire it back up.
Here's the test to see if you're hooked up:
1. Turn on the GPS and your ignition, so the speedo is on. Create a waypoint 2 miles (or whatever) from where you are and hit "GOTO' so it is tracking the point on the GPS. The DTW (dist to waypoint) on the GPS should read 2.0 mi.
2. Push the mode button on the speedo and move thru the screens until you see the DTW data on the right side - it should read "2.0 mi"
If it does, all the data the GPS can send - speed, time, direction, DTW, etc. will come thru fine.
Now get accurate speed, and new features. Like "gallons needed to waypoint" and most importantly, accurate MPG info. The gallons to waypoint is invalueable - let's say you're going across lake michigan and you want to know if you have enuf gas - take the boat out and get up to the speed you would use to make the crossing - now 'GOTO" the WP across the lake and choose the gallon to waypoint screen - it'll tell you how much you'll use to get there - also you get "range to empty" (at the speed you are at now) like in your car....
Note - the vesselview needs a a seperate harness for this - it comes with the vesselview - some boat builders throw it away....
