My 1995 502 in the 271 has about 650 hours and appears to have the origional exhaust.

Having lost a 454 in another boat due to water from a rotten manifold, I don't want a repeat.

I beleive the elbow is stainless but am not sure about the risers and manifolds.

Any recommendations, the oe Merc stuff is a
reasonable price.
It's an old boat and not exactly a hot rod, so I don't see
much sense in spending a buch of loot to gain a few mph.

Any ideas

Past time really. Pull them and check may be able to surface the gasket mating areaand reuse but the water passages are more than likely very restricted.

Tell tale signs (to me) water is leaking past the exhaust gasket. Pull the riser, clean up the surface and replace the gasket.

Change them. You are on borrowed time with those things.

Cheap insurance change them. 4 years is about the limit when we ran commercial boats with Mercs in saltwater without flushing.

the risers are stainless and you'll be able to tell cause they'll say "stainless" on the side of them, otherwise i agree with replacing the manifolds and spacers, your past due and it ain't worth toastin' an engine.

Water is leaking out! If water leaks in you'll be in the same boat as the 454!

Just put new motors in mine. Port motor dropped valve seat causing major problems and rebuild. Signs of
water leaking past gasket in to exhaust manifold. Mechanic says the most probable cause of the seat to fail is steam produced caused by the leak. I resurface all the surfaces and replaced all gaskets. I learned the hard way.