Lack of speed, limited trim range and porpoising!

[MDean89]

Hello All, just joined today.I have a 2003 Xpress H56 with an '03 Mercury 135hp Optimax. It has a four blade ss prop (not sure of the brand and it's stamped 251 P with the 5 crossed out, then underneath that it is stamped 19P 251). I have a 6" Pro HI-JACKER manual jack plate and outboard is mounted in the second from the top hole of the jack plate - it can be moved up one hole or down 3 from it's current mounted position. The best I can get is 41 mph and ~5100 rpms. If I trim up anymore from the 40-41 mph range the boat starts porpoising so I have to trim down resulting in slowing down. This is with just me in the boat, half tank of gas, cranking battery in back, live well empty and trolling motor batteries stowed up front with other gear. Seems I should get more speed and more trim range, but I don't know where to start. Hydrofoil, trim tabs, prop? Any tips or help would be greatly appreciated. Thanks in advance.

[Landem]

Probably need to post in the Xpress boats forum. There may be someone in there with a similar setup. I've owned several Xpress bass boats and it does take a lot of finessing to get them set up right. Also, if there are any dents on the bottom of the hull, it will kill your performance!

[BigFishSteve]

Scratch that..........."Well, you still have RPM's to use. So a lower pitched prop is a start"

I would not go lower than 19 pitch right now. You may need to get the nose up, and some of the hull out of the water and those RPM's will come right up.