Simrad
I have the same problem. I called Simrad tech support and they had me did deep into a menu on the unit. There was a number there that indicated interference with the compass. I relocated itge compass and the problem went away.
Hi, my Tolly 48 came with Cummins installed. They are 6BTA 300 hp. Plenty of engine, 20 knots, and very happy with them. We cruise fairly slow so I would be just as happy with a lower hp.