Exhaust Manifolds and Risers

[RoyR]

2008 Volvo Penta 5.0 GXi-G (freshwater boat only) - I have a new set of exhaust manifolds and risers, but when I took off one of the risers, it looks pretty good to me - would you leave them as is, or replace them?

Another question - why is it running so rich (black) how do I adjust the fuel air ratio?

 

[alldodge]

I would leave them. In most cases a fresh water man's and elbows don't need to be replaced

 

[ScottinAZ]

those risers look fine. Unless you have running issues, I wouldnt worry about the black in the manifolds. Most exhaust is soot covered on the inside to some extent. Being water cooled, these cannot by design get hot enough to burn it off..... IOW, dont go chasing a problem that may not exist, unless signs of being rich are elsewhere.