Blueing of header pipes.

I saw a comment on these forums that led me to think that blueing of the chrome header pipes could be an indication of the bike running too lean...too hot. Is this correct ?

I have noticed that on my 84 XJ900. It's got a stock airbox and a 4 into 1.

I'm not at home at the moment and plan on checking plug color, and also checking valve clearances and compression as soon as I get back....none of which I had much of a clue about till found this site. Thanks to all who have contributed.

The bike recently had a 'new' secondhand set of carbies put on it as the old ones were deemed 'too hard' by the closest Yamaha shop to where I live, but with winter,(weeks of rain, rain, rain), coming on in my part of Oz, rebuilding a set of carbies will be a project.

Chacal will be getting a sizeable order from Western Australia soon!

 

Aftermarket exhaust systems (like the 4-into-1 that you have) typically do turn blue. Factory pipes use "double-wall" header pipes, with the air space in-between the wall acting as insulation for the external chrome pipe....which is why you rarely see factory pipes turning blue.......the aftermarket pipes use a single-wall tube, and thus normally do turn blue.

 

Lean will turn your headers blue, check the colour of the plugs, if they are too lean fix it fast, too lean, no dam good..........

 

Thanks guys. I will start to put hours of reading XJbikes into practice when I get home.

 

Len is right, and single-wall pipes will turn blue no matter how rich you run, trust me (I own a Norton, remember?)

That being said, regular plug reads should be a normal part of your maintenance routine.