I just removed a Honda 7.5 Hp from my boat and I DO know this....I would not want to lift it on and off the transom unless I really had to, it is every bit of 77lbs. and feels heavier. You are a better man then me to even think about taking it home after every sail. I replaced my Honda with a smaller 57lb. Suzuki, and the difference in just lifting it out of the water while on the transom mount is huge. I would really wonder how many times I could do it.....before it went into the water, or I hurt myself, and I'm in good shape.
Sorry, I have nothing else to offer you.
Best of luck.