Suzuki 2 Strokes

Does anybody know why a T500 would have blueing at the header pipe.Am looking at buying this one but this has me worried,have not seen it on other T500s.or for that matter on any 2 stroke.owner says he replaced only one head because he said it showed signs of running hot??speedo shows 3950 miles.(1974)may be too good to be true.only work he has done is clutch main seal.

Changing a cylinder head is not the first thing I would have done if I suspected "running hot" (whatever he means by that). More likely to do with ign. timing being too far retarded and unburnt fuel heating the header as it goes down the pipe.

Cheers Geoff

Clogged baffles or silencers could cause excessive blueing of the headers. Or high temperatures caused by a lean mixture.