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Author Topic:   Installing SmartCraft On 40-HP Mercury Four-stroke
aubv posted 05-27-2006 12:33 PM ET (US)   Profile for aubv   Send Email to aubv  
SmartCraft Installation On 2005 130 Sport with 2005 Mercury 40-HP Four-stroke EFI Engine.

My first step was to remove the cowl on the engine and find the connector where the new wiring harness mated to the engine. Once this point was located, I hooked the wiring harness to the engine and to the SmartCraft Gauge and turned the ignition key to the ON position. This confirmed the gauge and cable functioned, and anything that happened from there meant I did something wrong. This particular installation required cutting the SmartCraft wiring harness as the plug on the wiring harness was to large to fit through the factory rigging hole that exists in the bottom of the forward seat under the helm area. (See picture) Before disconnecting the wiring harness and SmartCraft gauge and setting them aside, I determined the approximate location where I wanted to make the cut in the harness and did so.

I then removed all existing cable ties along the factory installed rigging mesh and removed the wiring and bracket from the back of the factory installed tachometer and removed the factory installed tachometer from the console.

PHOTO: Mercury Tachometer
The original tachometer.

In this case cutting the wiring harness solved a number of other problems including what to do with the excess cable (the shortest SmartCraft wiring harness is 20-feet), and how to use the factory installed rigging mesh and cable tie down points. Cutting the cable allowed the cable to be threaded from the helm area towards the stern, through the rigging mesh which terminates above the rigging hole in the bench seat. With the removal of all cable ties, the cut end of the wiring harness feed easily down the rigging mesh towards the stern far enough in to allow enough slack to make the connection to the SmartCraft Gauge. I plugged the harness into the SmartCraft Gauge and set it into the console. Once this length was established I then reinstalled cable ties to secure the entire rigging mesh bundle on the forward section.

I then move to the stern and made the engine connection by removing the factory end plug (See picture) threading the wiring harness through the lower cowl boot where the shift cables etc. enter the engine. Then I thread the wiring harness through the rigging mesh towards the bow. once I established the proper length of the engine section or the Wiring harness, I reinstalled the cable ties along this section of rigging mesh.

PHOTO: SmartCraft cable (blue) entering engine cowling
The new cable (blue) run into the engine cowling.

PHOTO: Cable and engine connector for SmartCraft
Connecting the new cable to the existing engine connector.

PHOTO: Cable run to dash panel
New cable run to dash panel.

At this point I now had both the forward and stern sections of the cable installed and all that was required was to cut for final length of the wiring harness then crimp and heat shrink the butt connectors. This was accomplished by carefully using a razor blade to score the outer sheathing on the wiring harness about two inches on each end, removing the sheathing, stripping the wires back the appropriate amount for the butt connectors, crimping the butt connectors on, and then carefully heat shrinking the butt connectors.

The last thing I did was take heat shrink tubing and place it over the ring terminals that had been connected to the factory installed tachometer and then heat shrink them. Then using one more cable ties I secured them to an anchor point so they would not be dangling inside the console.

PHOTO: SmartCraft tachometer
New SmartCraft instrument installed.

I then turned the key to the ON position again and found the gauge didn't work! After about one minute of thinking about what I had done I realized I had cut the wiring harness cable while it was attached to the engine and caused a 5-ampere fuse to blow.

Tools used:

--Wire cutters
--Wire Strippers
--Heat shrink gun
--Ratchet Crimping tool
--One deep well socket and socket driver
--Razor blade

Materials needed:

--(5)Heat shrink Butt Connectors
--(14)Cable ties
--Adhesive lined Heat shrink tubing

Time required was 45 minutes.


--Remove ground from battery terminal
--Remove Cowl from engine
--Cut existing cable ties along existing cable bundle
--Remove plug end from engine
--Cut cable to length if required
--Feed engine end cable through engine cowl boot
--Make plug connection at engine
--Remove existing gauge (socket driver and deep well socket)
--Install Gauge end of cable through rigging hole and cable bundle
--Run cable through Gauge ring
--Plug in cable to SmartCraft Gauge
--Insert Gauge into hole and tighten Gauge ring
--Crimp and heat shrink butt connectors if the cable was cut
--Check cable for play and secure cable bundle with cable ties
--Cover ring terminals on old wiring harness with heat shrink tubing and heat shrink.

glen e posted 05-27-2006 02:05 PM ET (US)     Profile for glen e  Send Email to glen e     
go to and look at the smartcraft guage section- you can get the bezel in variety of colors, or in chrome which really upgrades the look - all for 12 bucks or so and they just snap on and off with no tools needed...
Fish Stick posted 05-30-2006 12:54 PM ET (US)     Profile for Fish Stick  Send Email to Fish Stick     
For any one considering a Smart Craft gauge, the gauge shown, with the tach, is worth the small extra expense.

I upgraded from the standard display to this gauge recently because it provides more information at one time, and measures gallons used in tenths of a gallon, not whole gallons like the standard display.

The dealer and Mercury may steer you away from the Tach, because it is targeted for Verados and large Optimax, but it is a real treat to see the extra information on the one display.


jimh posted 11-28-2006 12:59 AM ET (US)     Profile for jimh  Send Email to jimh     
[Finally got a chance to add Brian's text to go with the pictures. I took six months off to do a little boating. :-) ]
cdz12250 posted 08-07-2007 08:23 PM ET (US)     Profile for cdz12250  Send Email to cdz12250     
I called Livorsi, whose SC1000-clone tachometer is the same exact gauge as Mercury's for about $100 less, and they told me that the cable you need is the 20-foot cable (two resistor). They're $79.
Nobleskydiver posted 03-15-2008 02:38 PM ET (US)     Profile for Nobleskydiver  Send Email to Nobleskydiver     
What other conditions does this supply? it oil pressure or water temp? BIll
jimh posted 03-15-2008 02:52 PM ET (US)     Profile for jimh  Send Email to jimh     
For information about Mercury SmartCraft instruments and exactly what information can be displayed, visit the SmartCraft website. The exact data available depends on the combination of the engine and the gauge. Mercury has a rather nice presentation of this information on their website. No need to try to repeat all of that here for every possible combination of engine and gauge. smartcraftataglance/engines/outboards.php

Leozepolusa posted 10-13-2008 09:59 PM ET (US)     Profile for Leozepolusa  Send Email to Leozepolusa     
I recently made this conversion on my 2005 Sport 130. It is really nice to finally take off the blinders and know how my engine is running. The only tweak I would make to the above step by step instructions is that I did not have to cut and splice the 20 ft. cable. The idea of doing that was unbearable. It turns out the connector on the gauge side of the extenstion will fit through the factory hole under the helm along with all the other existing cables. You just have to work it carefully with some force while pushing the existing lines back. I was also able to feed the connector extension through the cable sleeve using electrical fish tape and creating a cone shape immediately in front of the connector to reduce snagging. Having two people also helps to push and pull simultaneously. As far as the excess cable is concerned, I just neatly bundled it with zip ties and secured way up out of the way inside the console. I paid $275 for the SC1000 and $65 for the extension cable. Make sure you buy the right part number for each. There are many versions of similar gauges and extensions. Good Luck.
dinofun posted 10-14-2008 09:37 PM ET (US)     Profile for dinofun  Send Email to dinofun     
Don't know if this helps but there's a diagram here with part #'s for Mercurys Optimax engine
[I deleted this link because it was a third party diagram and contained errors in the designators used to identify the NMEA connections and reversed the context of the connection, showing an input as an output. Because of those errors I do not feel that it helps.--jimh]
jimh posted 10-14-2008 11:10 PM ET (US)     Profile for jimh  Send Email to jimh     
That third-party non-Mercury wiring diagram simply shows how to connect to the SmartCraft wiring harness to an NMEA-0183 device, presumably one which can supply speed data.

The Mercury instructions for installation are given in smartcraft_manuals/System_Sped_Tach_Install_Sheet.pdf

and show how to connect the SmartCraft system to a NMEA-0183 serial interface. Their instructions are rather lacking in any information about what NMEA sentences to send to the SmartCraft device from the NEMA-0183 device, but I imagine that the NMEA-0183 sentence RMC will suffice.

glen e posted 10-15-2008 09:17 AM ET (US)     Profile for glen e  Send Email to glen e     
corect - RMB and RMC is all you need....
jimh posted 10-15-2008 10:35 PM ET (US)     Profile for jimh  Send Email to jimh     
I don't think you need both RMB and RMC sentences. The RMB sentence contains navigation data related to an active way point. The RMC sentence contains navigation data from a GPS system. If both RMB and RMC are needed, could you explain why?
glen e posted 10-15-2008 11:28 PM ET (US)     Profile for glen e  Send Email to glen e     
becasue it needs speed data and waypoint data...see the functions of a smartcraft speedo connected to GPS....
jimh posted 10-16-2008 12:39 AM ET (US)     Profile for jimh  Send Email to jimh     
Glen--I don't think a 40-HP set-up with a single SmartCraft tachometer display can make much use of way point data. According to the Mercury chart, SmartCraft doesn't look like it even shows vessel speed data. I'm not sure why you'd connect the GPS at all with a 40-HP motor.
jimh posted 10-16-2008 01:02 AM ET (US)     Profile for jimh  Send Email to jimh     
The SmartCraft instrument installed in this discussion is the tachometer, and for a tachometer there is no GPS input connection. The GPS connection is only used with a SmartCraft Speedometer instrument.

The capabilities of the SmartCraft speedometer depend on the engine being used. This may seem odd to people who are used to the NMEA-2000 type instrumentation, but in SmartCraft the engine is the master controller on the network. Apparently the engine has to enable the data to be used, not the gauge itself. What's why the capabilities of the gauge change with the engine. Cf. page 4 of the manual (linked below) in which the data readout column is prefaced with the notation "DEPENDING ON ENGINE TYPE."

In the Mercury literature for the SmartCraft speedometer it does mention that the distance to a way point and the fuel needed to reach a way point can be displayed, and from that it is a reasonable inference that sentence RMB would be necessary to have sent from the GPS to the Speedometer, as RMB is the source of data about vessel navigation information to an active way point. However, in the Mercury literature this is not specifically mentioned.

There is no listing of what data is enabled with what engine, other than the chart (which I mentioned earlier and gave a hyperlink for).

SmartCraft Tachometer and Speedometer Operating Instructions: smartcraft_manuals/System_Tach_and%20Speed_Manual.pdf

glen e posted 10-16-2008 03:21 PM ET (US)     Profile for glen e  Send Email to glen e     
totally correct Jim - lost sight of the fact he is installing the tach...and the speedo in the post above got thrown in there - would need the NMEA sentances for the speedo - tach needs nothing....
glen e posted 10-16-2008 03:23 PM ET (US)     Profile for glen e  Send Email to glen e     
any SC speedo (or display) will show gallons used to WP if connected to a GPS that transmits RMB and RMC to it....
bloller posted 12-01-2008 08:26 PM ET (US)     Profile for bloller  Send Email to bloller     
I am interested in rigging my boat with SmartCraft. Exactly what information will this tach give me? Specifically will the troll control feature work for my 2004 60HP EFI? The Smartcraft website has a diagram that lists individual features for specific model engines but I does not state if this applies to all model years. I guess I should call Mercury to find out.
jimh posted 12-02-2008 10:18 PM ET (US)     Profile for jimh  Send Email to jimh     
As I mentioned previously:

For information about Mercury SmartCraft instruments and exactly what information can be displayed, visit the SmartCraft website. The exact data available depends on the combination of the engine and the gauge. Mercury has a rather nice presentation of this information on their website. No need to try to repeat all of that here for every possible combination of engine and gauge. smartcraftataglance/engines/outboards.php

bloller posted 12-03-2008 10:16 AM ET (US)     Profile for bloller  Send Email to bloller     
That table is of little help. One it does not state if the features apply to all model years and two it doesn't even include all the engines which are smartcraft ready(75-115 Fourstrokes.) Nowhere on the website does it state that the system tach will work for all smartcraft ready engines. Most dealer websites state that the system tach is for Optimax and Verado only but clearly it is not.
jimh posted 12-04-2008 12:02 AM ET (US)     Profile for jimh  Send Email to jimh     
I suggest you call Mercury and carefully probe their support staff for the information you are seeking. Then collect and organize what you learn, summing it up for us in a clearly written follow-up article. That's how information gets collected and shared in a collaborative on-line environment.

That's how this article you're reading came to exist. Brian installed a SmartCraft system, took great pictures of it, and wrote up his experience. I helped him publish it here.

It's too bad that Mercury hasn't clearly provided all of the information you are seeking. Since Mercury is more focused on new-motor with new-boat original sales, they don't seem to have provided a lot of do-it-yourself information about retro-fitting SmartCraft to existing installation.

bloller posted 12-04-2008 06:03 PM ET (US)     Profile for bloller  Send Email to bloller     
I was hoping the original poster, aubv, or I assume Brian or anyone with knowledge of this tach could tell me if the troll control feauture on his tach worked for his engine. That was the purpose of my original post.
jimh posted 12-04-2008 11:08 PM ET (US)     Profile for jimh  Send Email to jimh     
The Mercury feature "Troll Control" is listed on the chart I linked above. The chart shows that this feature is available on the 40 through 60-HP FOURSTROKE motors. Troll Control is included in the most basic feature set. I think it is reasonable to infer that since Troll Control is part of the minimal feature set of SmartCraft, if an engine has the SmartCraft decal on the cowling, it has that feature. According to the chart, there is no engine which has SmartCraft which does not have Troll Control.

Variation by model year and identification of a product by model year are touchy subjects at Mercury, because Mercury no longer recognizes model years. They dropped the notion of a product having a model year, at least in their public literature and public presentation. However, in some internal literature Mercury talks about "product year" to identify and differentiate among various models. Maybe you can get information from Mercury. I would think that a Mercury product specialist would be able to answer these questions with a telephone call.

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