Well im going to look at a used 25hp kohler mb sd sport today and was wondering if that will be enough motor for my 1546 all wellded alumacraft waterfowler? 2 ta 3 guys? Id be doing bps exhaust and intake right away. Or do i need to get something bigger? The boat is only rated for a 25 but owell

I don't see that being a problem. I run a 23GDSD on a 1644 and can run about 20 with me an another guy. Add one more guy (3 total) and a full cooler of ice and beer and I average about 16-17. So, since you will have a couple extra hp plus the aftermarket additions, you should be just fine.

1546 is a small boat for 3 guys, but that motor is enough to push it, just not real fast. Mudmotors suck at carrying a load, especially a big load in a small boat.

So in that case should i be going with a bigger motor?

No, you should be going with a bigger boat. Sounds funny, but its the truth.

If you are gonna have 3 guys all the time, or heck even if it's just you, I'd get something bigger. You wanna aim around 1854. That motor would probably push you better in an 18 foot than a 15.

not looking for a bigger boat just a motor that is going to work well on this boat. we have a 17 foot prodrive boat with a 35hp stage 3 for days with allot of guys and gear.

If all you are gonna use it for is 1 or 2 people and light gear, that will probably be fine. A 15 foot boat is not gonna carry much of a load.