When i was putting my engine back together i noticed there is something inside one of the manifolds that is clanking around. Are there flappers or something in them? I didnt have time to get into another project so i installed them and plan to figure it oit this winter. (In the middle of a kitchen remodel and dont have time to start another project). My boat does have rubber mounted flappers on the exhaust tips.

Anyone?

They should not have a rattle in them. Remove riser and have a look inside, perhaps a web between runners has broken? maybe try a magnet, in not remove and further investigate.
Be sure to use new riser gasket and hi temp silicone.

Will do. Something is definitly ratteling around.

Do you have exhaust tips or do the pipes go through the transom?

If you have tips, you may have internal flappers in the tips. Over time the rubber comes off and they rattle. Just look up into the pipe from the outside of the boat and see.

Exhaust tips with flappers. The noise is definitly inside the manifold. If i turn it upside down something falls around in there or if i shake it. Ill pull it back off and take the riser/tail off and see if i can see anything.

If the object inside is small you may be able to remove it, or at least identify it, by removing the lower water fittings.

Drained the water from the motor and manifolds the past weekend. (Keep the shop heated but you never know)

1. What ever it is is round/smooth cylinder shapped. I could feel it/move it with my finger. Guessing 3 inches long

2. Its the same thing on both manifolds. Same exact piece in both manifolds i can feel/ move through the drains but cant get it out

3. Stbd manifold drained no water. None!

4. Pulled the hose off the crossover and someobe has put a piece of airhose inside the water hose that diverts water to the manifolds. Wtf is with that? Some type of red neck water psi bypass?

5. I think i figured out why my oil temps were higher then i wanted. Main hose from the impeller to the cooler was twisted and kinked. Surprised there was any water getting to the oil cooler at all.

I have some work to do over the winter. It will be a week or so before i start on anything. To many irons in the fire rifht now.

It has got to fit through the fittings. How big around is it? Is it hollow? Have you tried using flexible magnet and/or claw tool. Might need to remove from top fitting.
That is strange.

Something left over inside from the casting process?