I took my boat out for the 1st time today. My question is it would turn 4000rps with a 19p prop an run 35 to 40mph. I would have thought it would be around 4500rpms. Its a 23xl nova with 260hp 5.7L. Any ideas??

I have spent a lot of time on a friends, with a 454 the seat of the pants speedo reads somewhere between 50 &55. You should be faster than 40 though....

My old merc 260 in my Baja 250 only turned around 4000 RPM. I was running upwards of 45MPH. How old is your motor? It may just be tired