Re: 7.5 HP outboard big enough?
Here's a bad pic of a Force one
Hey now,, you sayin' I'm a poor photographer...


(I probably am)
If running well, the 7.5 Force/Gamefisher is a stout little outboard. It's a de-tuned version of a Force 9.9/15HP outboard. On my jon boat I'm on plane in nothing flat. But,,, it's a different hull. Try the tilt pin in different locations, I can drop/pickup 3-5MPH in the different positions.
Also, make sure the outboard is running on both cylinders. I dropped an ignition coil and everything seemed to run OK (other than low idle) but the outboard was a dog, wouldn't plane. I replaced the ignition system it was back to normal.
I have a StingRay Jr. hydrofoil on mine and it helps pop the boat up on plane big time. I got it with the outboard, then heard they could cause excessive drag so I took it off, big mistake. It went right back on when I got home.