IM looking at putting a 12 hp copperhead on a 12ft boat brand of boat is undecided. Ive heard mixed reports about this issue. Some are saying if im going to go with 12 ft i need to go as wide as possible for example 1248. Others have said dosent matter as long as transom is 15 or 16". Im putting my money in the motor and looking at the boat to be expendable and would like to not have to special order a certain size. Any input on how that motor would perform with your average jon boat size of 1236? or narrower? Any input would be awesome!

I have a 1236 sneak boat that runs great. I would now ever not buy a 1236 regular hull. I am sure you would sink it. A 1248 would be much better.

that motor will run best on a 1436. 12ft is too short. you will drag ass and be slow. some guys are running that motor on 1636 phowlers. and run 18-20 mph. on a riveted 1436 you prob will see 25 mph and carry two people well. 1448 would do better with a load but im not sure of many companies that still make a 1448 riveted boat.

1248's are hard to come by up here in alaska, without special ordering. What might you recomend then on a regular alum hull? 10hp copperhead?

I have owned a 10, 12, and 18 Copperhead. 48" width is overkill for a Copperhead 12 but the 18 Copperhead is heavier so 36 inch bottom too skinny for the 18 on a normal square chine type hull. If it is a tapered chine hull like a Phowler where it gets wider the further down it goes into the water, then 36 inch bottom would be fine even with the 18 (I test drove a Phowler Sneak boat with that configuration and it was sweet). On square chine factory hulls, a 40" bottom is great for a 12 Copperhead and much more stable and less likely to flip than a 36" bottom hull. Tapered chine hulls are more stable for any given width (although even that depends on the design), but I do not know of too many besides the Phowlers as far as small boats go.

The performance gain going from the 10 to the 12 is worth every penny IMO. They have some other customers in Alaska (call and ask them). A 12 foot boat would work with a 12 Copperhead but will tend to ride bow high and stern low if you don't have some form of load in the front. 36" bottom boats (even 14' ones) are easy to flip if they are the normal factory square chine variety. Obviously a 14 will carry a load better, but unlike the above poster, I would put the 18 on a 16 footer rather than the 12.