I've got a 1648 riveted (heavy) Lundau with a 13hp Honda on a (rated for 30) Mud Buddy long tail. I just took it out for the first time this afternoon and she's SLOW! I about expected as much because of the weight/size of the boat. The shop I got the MB frame from gave me a 8x5 prop and said to try it out and if I thought it needed more/less prop they would swap it. It seemed to get the boat going easily but VERY slow. It had no problem revving to max rpm based on in and out of the water rpm. Does this sound like the right prop size. Again it's a heavy boat with a deck and there was me and another guy in it and I'm guessing 10 mph tops..... Nowhere close to planing.

Your thoughts?

A 23 vangaurd will nearly bolt right up, do that and a 9x6 prop because thats the only way you'll see an increase in speed.

Awesome! I'll be on the lookout. I started building this motor before I got the boat. Maybe I can sell the motor I have and find a 23 or bigger.

What kind of speed would I be looking at with a 23? I called the guy who I bought the frame from and he just got a 23 in on trade so I might just swap+cash for it. Will it still be under powered? Will I get at least 15mph? I'm guessing Boat/Motor/Gear/Me/Buddy = somewhere around 600 - 700 lbs.....