Re: stringer question/ help!
Okay....here's the thing about horse power ratings. It really doesn't have a lot to do with the actual strenght of the boat (some but not much) as it has to do with the overall performance. When a boat is way overpowered it can become very unstable at higher speeds.
The length of your boat has much to do with the power rating also, since the more wieght you have out front helps in the handling of the craft. I've been in boats rated for a 150, with 250's hanging on them and at high speeds the chine walk is terrible and very unsafe. This chine walk puts stress on the hull that is wasn't designed to handle.
We aren't saying that the larger HP will just sink the boat at all. It may be okay at certain speeds with an experienced operator, but for the average guy, it could be a disaster waiting to happen.
In all my restores over the years I've done boats rated at 125 up to 275 and the transoms are built the same, often the stringers are a bit heavier duty, but really not a lot of difference, the problem as I said is performance, for the most part it's just not safe.
If you want a high performance rig, there are plenty out there, so I'd suggest buying one that is rated for what you want it to do. The max HP on the rating plate is generally about 15% or so under what the factory has tested the craft at (a libility thing), so over rating slighty is probably okay, but rated 40 with a 100, just not a good idea.
If you want to overpower your craft that is your business, but personally all I can say is it's not safe and I (or anyone else here on this forum) is not going to say....."That's fine, go for it".
Insurance is also an issue, but the least of your worries if your dead from a boat wreck.