exhaust manifold riser

[lilet]

Hello,
I've got a Ski nautique 200 2010 with PCM 343, 1400hr, professional use in salt water.
I took off the risers in order to replace the gaskets but I've noticed that where
the water goes out from the elbow was pretty blocked from rust etc.
Inside where the fumes pass looks pretty rusty and it doesn't look smooth at all.
Do I need to buy new risers/elbows? Can I clean the old ones and how.

[Zach@n3]

1400 hours of useful life in salt water is pretty impressive. Do you flush after each use? I would say your best cleaning bet would be to take them to a hot tank at a local machine shop and see how they clean up. If that doesn't help then order some new ones.

[lilet]

No flush cause the boat is being used every day for six months i don't think that flushing will do anything while the boat is moored at the port untill next morning.
Thanks I'll try that.