1976 Sears Gamefisher 12 ft Boat Transom strength?

Question

I have a 12' fiberglass Sears Gamefisher boat from 1976. I just purchased a 9.8 HP Mercury motor for it and I am concerned it may be too powerfull for the back transom and may break the boat. The manufacturer's plate does state that the boat can take up to a 14 HP motor. Has anyone ever heard of a 10 HP motor breaking the back end of a boat, much less one like mine? I only ask because the fiberglass doesn't seem all too thick and does flex when I push down somewhat heavily on the lower unit of the Mercury when it is attached.

I don't want the boat and motor to end up on the bottom of the lake the first time I try the pair out.

Answer 1

you did NOT over power, you should be good to go, KEEP THAT PFD on at ALL TIMES !

Answer 2

If I was concerned about it flexing to much I'd bolt a piece of 1x6 to the transom. Make it long enough to go completely across.

Answer 3

if it's rated for up to 14 hp it should be fine with a 9.8 hp motor. As suggested you could add a piece of wood for extra strength.

Answer 4

Transoms on old boats often rot on the inside as they are wood covered with fiberglass. Keep an eye on it first few times out.

Answer 5

You should be good to go.  Tie a rope to the boat and motor in case.  Good luck.

Answer 6

if the transom flexes DO NOT put motor on boat and put in water... you need to add strength to your transom as they should not flex.. with your boat being the age that it is, it probably has a wood transom, 30 + years can play havoc on wood.

Answer 7

I once put a 20hp O/B on a seven foot pram dinghy. The stern flexed a bit, but at top speed (half revs) I achieved about six knots.

Reinforce the stern.