"Bucking" 25HP Motor at higher speeds

[Nederlager]

I don't have the boat anymore but maybe you can solve something that has been bothering me for a long time. Lifelong therapy on this forum!

In high school my brother and I were avid fishermen! And we couldn't afford a boat so shore fished all the time. One day our dad surprises us by pulling up to the garage with a 16' Aluminum boat with 25HP Evinrude on a trailer! Wow, we were excited!! He had to save for a very long time for the boat as we didn't have much money. He paid $1,500 I think. Keep in mind this was in over 30 years ago when you could buy a basic aluminum boat for $500 and a motor or $400, and get a good deal. This boat had a trailer, had front fishing deck built, was lined in astroturf....and (wait for it), had bucket cranberry color fishing "chairs" which were in a velvet type material. LOL! Not usual fishing chairs but these babies were right out of your living room type chairs! Built in arms, well rounded around our body. All that was missing was the foot rest! We'd get crazy, looks driving down the street with people taking photos! Hey, we were in high school, we didn't care! We had a boat!!!! Fun, happy memories to say the least with Dad. He has since passed and I wouldn't trade those memories of that pimped out boat for anything!

Okay to my post........ used 25HP Evinrude would "buck" at higher speeds. We could never figure out how to fix it. We tried mounting the thing at different levels because someone said it was from being mounted too low. But even when we raised it, it would still buck. It was fine at lower speeds, basically trolling speed, but as soon as you went any faster it was like a bareback bronc! Note: It was a "hollow hull". Hollow in the center of the entire length of the boat, solid left and right sides. Also, remembering back, the spot where the motor was mounted was scooped down about 4" inches. I'm wondering if the entire boat wasn't custom built and that scoop down made the motor entirely way too low no matter what trim height we set it at?

Thanks for figuring out what it could have been. Has been bothering me all these years because Dad felt bad he got taken and failed us boys. But in truth Dad, it was the greatest gift you ever gave us boys! The bucking made it even more of an adventure with great memories fishing with you! Thank you Dad!