Sorry buddy, certainly not my intention to interrupt a sale. Just pointing out there is a LOT of mis-info about on doing this....including from suzuki as my own experience proves. if the OP doesn't have a plotter than i'd recommend the gauge....just so happens i know where one is for sale!
depending on the age of the motor will depend on the type of SMIS connector the motor has. I have the new square plug, older engines have a round port if memory serves (i didn't pay a lot of attention to it as it didn't apply to my engine i have to admit, so double check). you may need a gender change cable to the SMIS adapter to whack it into a suitable chartplotter.
i have my sooz connected to my garmin 750 and 551s, i'm currently doing accuracy tests but the numbers seem in the ball park anyway....note....the piccy has the plotter set to USA gallons, it is therefore over reading. I changed it today but you get idea. i did wonder why the 551 was showing 1 gallon ish per hour less than the 750
the cheapest way to get NMEA seems to be a garmin network starter kit if that matters to anyone.