Exhaust/muffler etc

[brak]

I need to replace my main exhaust hose this year. The engine connects to one of those wet mufflers (that look like round black can with entrance for exhaust and also, I think, water connection - it sits behind the engine so it's one of the hardest things to access).

Anyway, from there a long run of exhaust hose goes to the stern to original fitting (from previous engine) which is a 180 degree elbow above waterline, and then a large rubber bell type fitting that connects to thru-hull. I haven't taken the rubber fitting apart but I am fairly sure it would have a one way valve , flapper or diaphragm - either way to keep the water out, since exhaust thru hull is pretty close to water surface.

Question is:
1) Can I get rid of the 180 degree metal fitting and just make the 180 elbow out of exhaust hose (perhaps the actual 180 degree could be a hard fitting but the rest would be made of the hose). I think the answer is yes - but I don't want to miss anything. The original fitting is very large and somewhat rusted, I think it is time for it to go.

2) Where would I source a new "rubber thing" - flapper/one way valve for the exhaust? What I find online seems to have external flapper which in my case would not provide sufficient protection.

[PBzeer]

My exhaust hose goes from the water-lift muffler to the rear of the boat, with a loop (not vented, and well above the waterline) before going back down to the thru-hull.

[brak]

Cool, now I only need to figure out what the rubber thing is and where I get a replacement.

[negrini]

Brak, you'll need a lot of room to make 180 without an elbow and not bend your hose. Mine rounds the entire rear compartment, but works perfectly. If you raise it correctly well above waterline, and considering your waterlocker has correct size as well, you don't need a flap at all. That thing is mostly used on powerboats wich require straight exhaust to handle more powerful beasts.

[doons60]

I spent this past Saturday in my engine department and can offer you two thoughts.
New exhaust hose is not all that flexible, nor is it very inexpensive. Depending upon the radius of the 180 you may have a hard time making the bend required.
Due to the flexibility of the hose you might need a good bit of leverage to make the turn, due to the size of the engine compartment this might prove challenging.
Good Luck

[brak]

All good advice, but I do wonder about that bell shaped valve. Anyone knows what they are or who made them?