It isn't so much the shear weight, but the distribution... and frankly they just don't put the lift points in the right places.

My 3.5HP is 41 pounds... I can just wield that about. The boat itself is 65 pounds... and all wieldy.

When I launch from the slip... the limited room means moving the boat is a chore, but once the dink is in the water, I can muscle the motor onto it OK.

The key is to launch everything from the mother ship... from which I use a 4:1 tackle and all the lifts are fingertip easy... at that point it doesn't matter if the motor is 41 pounds heavy or 55 pounds heavy. But of course the result is a lot more HP to zip around with. 3.5 HP is enough to move the dink about at just short of a plane... but the .26 gallon tank runs out quickly... this is where larger engine and separate fuel tank make the difference.

Heck if you have that motor crane... should be easy peezy raising and lowering the motor.

I use the mainsheet to hold my tackle in place and work very carefully. Maybe one day I'll get a crane.