Topic: MAC Exhaust Discoloration - One of These Things is Not Like The Others

[cshanek]

I recently bought and installed a Mac 4into1 exhaust system for my 76 CB750 K6. I read while shopping about the blueing/discoloration that was expected, but after several rides, I noticed the cylinder 1 was the only header that hadn't changed colors (see attached). I initially figured it was misfiring or having another issue, perhaps running really rich ... but fired up the bike for 10-20 seconds on several occasions and all 4 headers felt identical to the touch. I also melted a glove on it when I got home after a longer ride.

Any ideas as to why it hasn't changed color? I am actually considering taking a torch to it for consistency's sake.

[Trevor from Warragul]

I have one pipe on my CBX that isn't as discolored as the others. The bike runs perfectly, so I choose to ignore it...

[robvangulik]

Maybe slightly thicker material, or better chromed, in another batch?

[Erny]

I would say that cylinder runs bit richer

[spotty]

look on the bright side, when its parked on the side stand it won't be any where near as noticeable