Don't know if this helps but I took my searider out for the first time last week. I havn't found a outboard for it yet so used my 5hp tohatsu. I was very suprised to see that this outboard got it on the plane with 2 people
!! This was on very flat water about 15mph on gps.
My searider is likely to be very light compared to yours (see pic). But I found it planed alot easier with one person up front.
I think that weight up front will make a big improvement. Also the flooding hull (if yours has one) takes some getting used to.