I had to replace the outboard motor on my 1983 compac 16. My old motor weighed 35 pounds, the new motor weighs 50 pounds. Can my old compac handle that much weight?
No personal experience on a 16, but you should be OK. You're right to be concerned, but it's only 15 lbs. It shouldn't be hard to find some weight to to offload or shift forward if necessary. I do use a spirit level to test trim if I've made big changes. 15 lbs. shouldn't be a problem.
If your concern is the stress of the transom, you can place a backer board on the inside to help distribute the weight.
The boat will be fine. However if you have a folding motor mount like a Garelick, make sure it's rated for the weight. They come in various weight rating levels.
Be careful when trailering, if you leave the motor on the mount (I don't). Bouncing on the highway is more stressful. Either secure the motor so it won't bounce, or take it off the boat.
Wes
I can"t answer your original question never owning a 16. And if it is a done deal, you've gotten some good advice from those who posted before me, particularly about not towing long distances with the motor mounted, that produces much more stress on everything than operating in the water.
I will say that I went the other way with my 23. Removed a 104 lb. motor and replaced it with a 59 lb. motor. My sailing life got a lot better. It eliminated "squat" when motoring with the shipping of water through the scuppers and improved the sailing trim noticeably. Additionally that heavy motor was hard to lift even with the spring assist mount while the lighter is a breeze. The heavy motor was also very difficult to remove for travel. If it is a short distance, thirty-five miles, my house to marina on the smooth Natchez Trace Parkway, I just strap the motor to the stern rails so as to not stress the mount or transom. As an added benefit I removed the start battery, eliminating some more aft end weight.
I had a better place for that heavy motor, so nothing was wasted.
Experimentation will answer your question and allow you to adapt the new motor, I think.
Thank you all. That is very helpful.