Jeff, I use a Garmin 276 on the boat. you might try a google search for what you are needing.

I bought 2K diesel generator for our bus a few months ago and it is still in MN. at our sons home, we were on the Harley. I will be picking in up in early Dec. so I can talk more on this later. I still think it is a good idea. I didn't want a gas since I have huge diesel tank. I going to park mine right next to the big one.