Exhaust Discoloration?
 

Why and how to stop the rusty-looking patches from getting darker?
Fresh water boat. Motors run cool.

Wots the deal? Thanks. D911

Re: Exhaust Discoloration?
 

What kind of exhaust is that and what's it made of??????? :confused: :confused:

Never seen or heard of anything like that before. It almost looks like its painted and the paint is burning.

Re: Exhaust Discoloration?
 

With that little tab welded on the the riser, it looks lIke and older Gil to me.
Are those hot spots? Could the water preasure be to low to get enough cooling? They do look painted.

Re: Exhaust Discoloration?
 

Yes, older Gils.

Painted...I don't think so, but someone here should know if metallic finish was availabile?

More feedback please...D911

Re: Exhaust Discoloration?
 

Dave,
I would run the engine and see if that spot on the port riser is significantly hotter than the starboard riser. If it is, my guess is that the port side is being starved for water or the cooling water it's getting is exiting too quickly to properly cool the top portion of that riser. If it's starved for water it could be as simple as a crimped hose or different routing of the hoses. Mine are SM and they don't route their hoses that way, rather all four hoses go to bottom of manifold. If it's exiting too quickly, the risers might need modifying to dam up the bottom portion to ensure the whole riser remains full of water but I'd check with the manufacturer before modifying anything.
Phil

Re: Exhaust Discoloration?
 

Gil marine's email is broken....bummer. Anyone a pro on these things? Thanks

Re: Exhaust Discoloration?
 

Certainly not a pro, but my advise is priced accordingly. :D

Re: Exhaust Discoloration?
 

Called GIL, they were zero help. :mad:
Will find a good local mechanic...i heard something about Matt's Mobile Repair in the Newport Beach Ca area...

Thanks guys.:drink:

Re: Exhaust Discoloration?
 

Honestly, it just looks like they BOTH need repainting. You also have the same colored rust spots on the flanges of both manifolds. Maybe the paint was just thin at that point in the elbow.

Also are those exhaust pipe hose clamps tight. You may be getting a little water spitting onto the elbow.

Michael

Michael

Re: Exhaust Discoloration?
 

I would say they are painted. Look around the riser bolt in the first pic. Its looks like its chipping.

Probably a combo of hot spots where its discolored and the paint type used.

The only Gil risers I have ever seen have been polished SS and the Manifolds are black powdercoated. Somebody probably painted them.