Sorry...
Your 741 display can only display information that is inputted from some sort of sensor somewhere...the only exeception being your GPS position, which comes from an internal GPS antenna in the 741.
The depth must be coming from a transducer, probably on or near the transom, that is plugged directly into the 741, or, if you have one, plugged into a network 'backbone' of connectors (N2K network) and the 741 is plugged into that. A starter Garmin network backbone runs about $70 and many owners have installed them. If you had installed one, you would remember doing so. If I had followed the directions precisely, it would have taken half the time.
The fuel flow info must be coming from a transducer/sensor, probably on or near the fuel line to the engine (like the Garmin GFS10 sensors, $150 each), or from the engine itself via a plug under the cowling (for 2006 and later engines). There are multiple iterations available in YamaWorld, but ultimately there are only those 2 sources of data for engine fuel flow. Fuel line sensors are not accurate at idle because dollops of fuel are irregularly pulled into a tank on the engine and run the engine until that VST empties.
I'm curious whether any other Yamaha owners have tried the hack I described in my 'Extracting Engine Data..." post and wondered if you had done it, but obviously not, because it is a bleeding-knuckles 3 beers per engine adventure that you would remember. However, for the price of 2 $90 Lowrance cables (and some large Band-Aids), you can extract more info directly to the multfunction plotter display you already own without paying $1,100 each for the 'proper' Yamaha gauges. Just say'ing.
I'll figure it out when we see your boat and gauges.
Roger,
I would tend to agree, except that a bunch of other engine parameters (3 pages) would be available and showing unless Ken de-selected them all, including eng volts, temp, rpm, trim, oil press, etc etc.
The story of how how the US came into possession of that then-state of the art Russian radar is hilarious, but for another time.
Stay safe!
John