I am looking at at 1985 GW Trophy Pro 257 with the original twin Yamaha 115 2 strokes. The motors start right up and sound good and the owner claims to get max speed of 40 mph. Are these motors underpowered for this boat? I checked into getting a twin 175 Suzuki 4 strokes and the 1st price I got was close to $30K. Thoughts? Thanks