Discoloration of Exhaust outlet pipes - normal?

[Dirt_McGert]

Sorry for all the noob/lame questions, I'm completely new to bikes.

Is minor discoloration of the leading exhaust pipes (right by the engine) normal? If you search the bike pics on this forum, you'll see some discoloration of these, most of which look like mine. It's not black, just some goldish, bluish discoloration, which ends before the curve downwards of the pipes.

Is this normal? Or does it mean the engine has been severely overheated in the past?

Yeah, I'm paranoid lol

[Dupo]

On these bikes its normal. They are set to run lean from the factory. Heat = blueing. Just as if you would put a torch to the pipe...it will turn blue.

if you want to remedy the lean setting ... go to our 'how to' section and check out the needle shim mod.

severely overheated pipes ... you would be looking at VERY blue pipes extending about 8-10 inches beyond the head.

[Dirt_McGert]

Ohhh ok, yeah it's fine then. It's probably leads about 4 or so inches away from the head.

[Dupo]

Yea, then thats normal.

[Badbob]

I like blue. :)

[Dirt_McGert]

Actually it's about 5 or 6 inches away from the head, ends in the middle of the curve. No biggee, just thought I'd get the facts straight.

[Bill]

There are compounds that you can use to buff this out if it bothers you. Any cycle shop should have this available.

Cheers!

[Dirt_McGert]

Cool, thanks. Might have to check it out, but it doesn't really bother me I guess haha.

[Gadzooks Mike]

Do the shim mod. Besides keeping the pipes from getting blue, it might also take care of the backfire when you shut it down.

[Dirt_McGert]

http://www.gz250bike.com/viewtopic.php?t=15

That one right there? The needle shim mod?

[Dupo]

Yep

[Gadzooks Mike]

That's the one. It takes about 15 minutes and is well worth the trouble.

[Dirt_McGert]

I'll try it once I get some time (in about a week.)

It does it off and on..... it seems like whenever I go somewhere and shut it off, it doesn't do it, then when I leave and come back home, it backfires at my house..... possibly because of a warmer engine?

[Gadzooks Mike]

Possibly. My guess is that since it's running lean, it's running too hot. If it's running too hot, it will cause it to backfire. I'm not a mechanic by any means, but this is what I've read about it. I've also read that the Suzuki S40s are known far and wide for this, and must be set to run richer or the backfires are unbearable. I didn't wait for my GZ to be broken in before I did the needle shim mod, and it runs like a champ. I'm not sure running it lean is any better for it than not, broken in or not. But like I said, I'm no mechanic. Maybe some of these gurus in here can add to this, and correct me if I'm wrong.