Burnt Exhaust Pipes

Raul Silva · Sep 19, 2017

Hell friends,
Whenever I place new and recently chromed exhaust pipes in my Norton Commandos, shortly after the engine starts running, the curves of the exhaust pipe turn yellow, like they are burnt.
Is this normal or is there any way to prevent this from happening? Is it possible to keep the exhaust pipes chromed?
Thank you for your help
Hope to hear back from anyone
Raul

baz · Sep 19, 2017

Yes it's normal

htown16 · Sep 19, 2017

If straw yellow or gold it means your engine is in proper tune with modern gas. Blue and you are starting to get a little lean but probably still okay. There are ways of treating the pipe inside to prevent it. To me it shows the bike is ridden. I wouldn't worry about it. If the pipes match side to side that's good, means the cylinders are balanced.

ashman · Sep 19, 2017

Its because the curves on the headers are the hottest part when running that is why they change colour.

Ashley

Biscuit · Sep 19, 2017

htown16 said:
If straw yellow or gold it means your engine is in proper tune with modern gas. Blue and you are starting to get a little lean but probably still okay.
.

I've owned my '75 since new. The pipes are the original, crossover and all. I guess the pipes may have gradually turned from a nice golden to what they are now - a kind of multi-hued blue ranging from lightish to a dull really dark blue, burnt-brown-gold. They are to me the mark of a well used well cared for, well running Commando. There IS a simple way to keep the pipes' chrome nicely pristine, never ride it. Or you could research coating the inside and riding it easy once in a while. I've heard that may work. Or you could just say "the hell with pretty pipes", ride it as it was meant to be ridden and enjoy the look of a bike with blue-brown pipes. It's the look of a Norton.

gripper · Sep 20, 2017

You could consider a couple of turns of copper wire (about 1mm dia) around the exhaust pipes right next to the cylinder head nuts, (you can loop it onto the nut fins) the copper will conduct heat away from the pipe and may stop your pipes turning colour. a strip of copper would have the same effect, how you fix it is up to you.

eskasteve · Sep 20, 2017

You can have the inside of the headers ceramic coated or if you're thrifty (cheap) like me you can use VHT Header spray paint. I used almost a can per pipe in my new Viking headers and It has worked very well.

Torontonian · Sep 20, 2017

With new pipes or mufflers I spray or pour the VHT paint inside , swirl things about , then pour off. Seems to help with discoloration and makes the system last a bit longer. Unless it fractures and goes tumbling/ sliding down the road. :wink:

Raul Silva · Sep 26, 2017

Hello friends! I thank all of your for your feedback and I guess I'll just continue riding my Norton! To hell with the pristine exhausts!
Thank you!

Fast Eddie · Sep 26, 2017

Raul Silva said:
Hello friends! I thank all of your for your feedback and I guess I'll just continue riding my Norton! To hell with the pristine exhausts!
Thank you!

Looks pretty pristine to me !!

lazyeye6 · Sep 26, 2017

I hear your pain!
I had great success coating the inside of the pipes on my 70 Triumph with Kreem Blue. They turned only a faint blush yellow at the first bend.
I used this product on a set of Commando pipes and it didn't seem to do much of anything. They turned blue at the bend. The Triumph
exhaust has a bigger inside diameter.

Nice Sunbeam!......and Commando!

Mr. Rick · Sep 26, 2017

Blue headers: The official badge of authenticity and roadworthiness.
Sweet looking machine you have there!

kerinorton · Sep 26, 2017

After riding my bike for 3,150 miles over 2 weeks in January, through four seasons of weather, the shiny chrome just about disappeared from my new pipes. They have both gone golden blue to matt silver. Enjoy the riding.
Dereck

Burnt Exhaust Pipes

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