CajunCowboy, I checked the specifications of the Honda 90 four stroke, and it looks like the weight of it is just under the weight limit of 388 pounds for a 170CC, which is rated for a maximum 75 HP. What is your top speed with the 90 HP on your boat? I bet you get a nice hole shot with the 90 HP.
I had a 150CC that was rated at 60 HP with a 250 pound maximum weight. I had a Yamaha 50 HP on it, and I replaced it with a 2 stroke 70 HP, which worked out nice on that boat. This is the thread that I wrote for the meet and greet,
Triumph 150CC with Yamaha 70TLR