Does anyone know when Fountain changed their materials used for their transoms and stringers to solve the moister issues.

The materials were not the issue the way they did the exhaust sealing was the issue. Doesn't matter if its composite or not leaking isn't good.

As for when they went composite it is all over the map, two of the same boat same years one may be wood one may be composite. In general 2007 ish

Thanks for that information!