I have a MK ultrex I pilot with integrated gps system and sonar transducer. What hummingbird bird unit would match with it ? Thinking about helix 7 MSI, MDi, GPS . 

18 minutes ago, Terrel said:

I have a MK ultrex I pilot with integrated gps system and sonar transducer. What hummingbird bird unit would match with it ? Thinking about helix 7 MSI, MDi, GPS . 

Correct me if I'm wrong,with the troll motor built in transducer being sonar. Side imaging and down image won't work.

It all depends on which transducer is in the trolling motor.   If it’s the universal transducer it is only 2D sonar and you will need an adapter cable to connect to the fish finder of your choice. Newer Ultrex have different transducer options that include down imaging and side imaging.

And for the helix, you will need an N unit. Given the sales going, a g4N will be the best option for price. The rest of the letters are the functionality. If you want side imaging you need an MSI. And it will give you all of the other functions with it (gps, mdi, 2d chirp). 

Its a older ultrex and it has 2d sonar.

You still need an N model. You’ll get 2d from the ultrex. Then your side imaging will have to be from the stern transducer.