Water leaking at exhaust collectors??

[bshumm]

I have a 1987 SeaRay 270 with twin 260hp (GM 350's) mercruisers with alpha 1 outdrives, when I fire the starboard engine up with the earmuffs on, I have water leaking into the bilge, after turning the engine off, I noticed that the water is leaking faster for a couple of seconds. When I looked for the source of the water, it looked like it was leaking at the transome where the exhaust collectors bolt onto the inner transome plate. Is this a common problem? Also what is the best way to go about fixing it? Please advise.

Thank You,
BSHUMM