125 HP on my 1975 20' SF..Under powered ?

[Texascoastalfish]

Well I just bought the boat and it had the 200 on it. I have it in the shop getting tuned and gone through. I haven't run it yet on the water. I guess its just a fuel consumption issue mostly, I hear the old Johnsons are pretty thirsty, and I would like to have newer maintained motor on it. In Fact After it comes back from my mechanic I'm probably going to try and trade it for something in the 140-150 range. My soon to be Brother in law has the Force on an old Bayliner, but in reading about the Force outboards I hear horsepower ratings were not taken from the prop thus meaning a 125 may be a 100 as compared to other outboards. I just dont want to have to be running WOT at cruising speed.