Davidtav Posted November 2, 2021 Share Posted November 2, 2021 I have a Kawasaki Z650. Almost three years old. Had it from new. Been serviced at main dealers regularly. All seems to work perfectly. … one thing that irritates me a bit though is that the exhaust headers have developed this blue tinge. Now I know, from a Facebook group, this isn’t exceptional. But to me it does seem wrong. Makes me think the bike is getting too hot. Possibly running a bit lean. The temperature gauge seems to work ok. The fan comes on properly when sat in traffic. The blue tinge has become more noticeable over the last 12 months. As I’ve started to ride it more spiritedly perhaps … anyway I just wondered what you guys think? Should I be concerned at all? Or just accept this is what modern bikes are like? … yes I know the bike needs a clean! Heres a pic Quote Link to comment Share on other sites More sharing options...
bonio Posted November 2, 2021 Share Posted November 2, 2021 Pretty normal, I think. Harpic is good for getting it off. Try a bit where it doesn't show first, just to be sure. 2 Quote Link to comment Share on other sites More sharing options...
Ian Frog Posted November 2, 2021 Share Posted November 2, 2021 @bonio is perfectly correct about the harpic but please ensure it is the max strength one in the black bottle ! Think yourself lucky you don`t own a 60`s Norton or Triumph or the tightly bending BMW flat twins as blue was definitely prevalent. Cheers Ian 2 Quote Link to comment Share on other sites More sharing options...
Gerontious Posted November 2, 2021 Share Posted November 2, 2021 (edited) Its completely normal.. forget about it. heat steel to 500c or higher and it turns blue. you can clean it if you want but it will only happen again. and again. and again. Edited November 2, 2021 by Gerontious 4 Quote Link to comment Share on other sites More sharing options...
geofferz Posted November 2, 2021 Share Posted November 2, 2021 Mmmm blue - embrace it! 1 1 Quote Link to comment Share on other sites More sharing options...
Mississippi Bullfrog Posted November 3, 2021 Share Posted November 3, 2021 Funnily enough I was just reading a post on the Bobber forum where a guy was complaining his headers hadn't changed colour. The advice was to go out and ride it properly. 2 3 Quote Link to comment Share on other sites More sharing options...
Bender Posted November 3, 2021 Share Posted November 3, 2021 40 minutes ago, Mississippi Bullfrog said: Funnily enough I was just reading a post on the Bobber forum where a guy was complaining his headers hadn't changed colour. The advice was to go out and ride it properly. Yup got to get hot enough or its not going to happen Quote Link to comment Share on other sites More sharing options...
Trooper74 Posted November 3, 2021 Share Posted November 3, 2021 The header on my Himalayan has gone a light brown, like most Himalayans. Stainless steel but possibly not the best grade ... looks ok though. Quote Link to comment Share on other sites More sharing options...
Bender Posted November 3, 2021 Share Posted November 3, 2021 15 minutes ago, Trooper74 said: The header on my Himalayan has gone a light brown, like most Himalayans. Stainless steel but possibly not the best grade ... looks ok though. Stainless goes different colours depending on heat, brown indicates not overly hot. 2 Quote Link to comment Share on other sites More sharing options...
Fozzie Posted November 3, 2021 Share Posted November 3, 2021 The Kawasaki Z650 is basically the old ER in a new name, and it does run lean when it's in eco mode. It does this to save fuel, so if you cruise at 70mph it will blue up those pipes over time as the exhaust temp will increase. Nothing to worry about, all part of the normal operation of the bike to meet EU emission rules. Doesn't seem to have impacted reliability. 1 Quote Link to comment Share on other sites More sharing options...
Marino Posted November 3, 2021 Share Posted November 3, 2021 It has to be blue. I would paint mine if don’t become blue 2 Quote Link to comment Share on other sites More sharing options...
linuxrob Posted November 3, 2021 Share Posted November 3, 2021 Please be careful using any product that contains Hydrochloric acid on 300 series stainless steel parts. It can cause pitting and stress cracking, some grades are more corrosion resistant. Just use Harpic etc in the loo. 2 Quote Link to comment Share on other sites More sharing options...
Trooper74 Posted November 3, 2021 Share Posted November 3, 2021 The “Patina of Age” .... just leave it alone .... Quote Link to comment Share on other sites More sharing options...
skyrider Posted November 3, 2021 Share Posted November 3, 2021 1 hour ago, Trooper74 said: The “Patina of Age” .... just leave it alone .... patina thats what they usually call rust 1 Quote Link to comment Share on other sites More sharing options...
Bender Posted November 3, 2021 Share Posted November 3, 2021 2 minutes ago, skyrider said: patina thats what they usually call rust Or as the Chinese say OEM 3 Quote Link to comment Share on other sites More sharing options...
billy sugger Posted November 3, 2021 Share Posted November 3, 2021 51 minutes ago, Bender said: Or as the Chinese say OEM They probably have a paint code for it 1 Quote Link to comment Share on other sites More sharing options...
husoi Posted November 4, 2021 Share Posted November 4, 2021 Technically, if your mpg is really poor then the blue colour could mean an extra rich mix that makes the engine run hot. Quote Link to comment Share on other sites More sharing options...
fastbob Posted November 4, 2021 Share Posted November 4, 2021 Don't touch it , especially with Bog Cleaner ! Quote Link to comment Share on other sites More sharing options...
Davidtav Posted November 4, 2021 Author Share Posted November 4, 2021 Hi. Thanks for the replies. I will leave it alone. 2 Quote Link to comment Share on other sites More sharing options...
Mississippi Bullfrog Posted November 4, 2021 Share Posted November 4, 2021 5 hours ago, husoi said: Technically, if your mpg is really poor then the blue colour could mean an extra rich mix that makes the engine run hot. Eh? I thought it was a lean mix that ran hot. 1 Quote Link to comment Share on other sites More sharing options...
husoi Posted November 4, 2021 Share Posted November 4, 2021 12 minutes ago, Mississippi Bullfrog said: Eh? I thought it was a lean mix that ran hot. Sorry, got the wrong mix lean mix = hot engine Quote Link to comment Share on other sites More sharing options...
billy sugger Posted November 4, 2021 Share Posted November 4, 2021 3 hours ago, husoi said: Sorry, got the wrong mix lean mix = hot engine Here's a way to remember. Never LEAN on a HOT engine, you may burn your arse 1 Quote Link to comment Share on other sites More sharing options...
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