What happened here?

[Bbqjoe]

Of course this was caused by heat, but how.
This is the only place on the pipe, the rest looks fine.
This is on my wife's Yamaha Vstar.
It came to us this way.

 

[chancer]

When engines run lean they create more heat causing this.
Or any other reason the exhaust got over heated.
Or cheap chrome?

 

[Bbqjoe]

When engines run lean they create more heat causing this.
Or any other reason the exhaust got over heated.
Or cheap chrome?

Yes Mr observative.
But the rest of the pipe is fine. Why would this heat only appear at the end of the exhaust, and not at the headers?

And if you don't know, would you please go sit at the back of the class, and let others have a try?

 

[Whitetrashrocker]

Cheap chrome.
The cool coloring is at the first bend.

 

[Bbqjoe]

Cheap chrome.
The cool coloring is at the first bend.

This isn't at the first bend man.
It's almost at the end of the muffler.
Please notice rear wheel, and lack of header and engine in pic.

 

[chancer]

Still Joe. This part is just the exhaust tip or muffler cheap chrome. The header itself is probably better chrome.

 

[Denny]

Sometimes tire dressing sprayed on the pipes will turn them blue like that. Does the blue color look like tiny little drops? A lemon cut in half and rubbed on, or a good chrome polish should take that out. Good luck.


Denny

 

[itsid]

likely there's a baffle plate at that spot.

And for some reason (PO messed with the internals of the muffler *cough*)
it's collecting an excess of the heat causing the discoloration.
IIRC the final exhaust pipe (the internal pipe connecting the last two baffle plates )
sits at an angle ... chances are the discoloration happens close to where the pipe pokes through the second to last baffle plate.

(more material to collect ehat internally)

then all you need is a saddle bag or heel to block outside airflow for long enough... and
the rest is on the picture you made

'sid

 

[Whitetrashrocker]

This isn't at the first bend man.
It's almost at the end of the muffler.
Please notice rear wheel, and lack of header and engine in pic.

Duh

 

[Hellion]

Sometimes tire dressing sprayed on the pipes will turn them blue like that....

I agree on the possibility. Much like the way you accidentally get finger oil on a halogen bulb, the bulb gets extremely hot in that localized area and FOOM, it destroys the bulb.

I'm thinking something oily was there at one time. Tire dressing, a misfire from a WD-40 can, anything.

Who cares. A little blemish adds character.

Polish it out with metal polish, water & aluminum foil rub or #0000 (super fine) steel wool.

 

[itsid]

I doubt steel wool is even needed.. looks like toothpaste / soft cloth could do the job just fine

'sid

 

[mightyraze]

Vapor from the bottom pipe burning/tarnishing the top pipe?

 

[KartFab]

Is that a spot where the inside diameter of the exhaust pathway changes from large to small?

Why is it that when it snows, the air warms up?

Is this a spot where exhaust pressure waves hit each other?

Im clueless though, just some thoughts. Theories. Time to go to the back of the classroom and throw paper airplanes.

 

[Flyinhillbilly]

If I remember right, those v stars have an air injection sort of thing that cracks and lets air into the exhaust stream causing it to ignite again when it gets to the muffler. Look for a little metal tube at the base of the jugs.

 

[Bbqjoe]

I may have got to the bottom of all this.
The bike started when it was trailered.
It barely started when I got it home.
The next day, it didn't want to start at all.

I pulled the plugs, and they were pretty carbed up.
I sand blasted them, checked the gap, and it fired right up.
I also found out that the shop they took it to, which is a complete POS, installed too cold of plugs. The manufacturer calls for 7's and 9's were installed. Also not a good thing at idle.

I think somewhere right before I picked this up, it was started, and the choke was left on too long.

The manual says when this happens, the pipes can become discolored.

I'm not 100% positive on this theory, but it may be plausible.