I'm about to purchase a used 96 VT1100. The owner swears it is stock and he purchased it new. It only has 3600 miles on it, looks pretty darn good except for the blue on the first 3 inches of the front header pipe. No blueing on the rear one. Doesn't sound like it's leaking and the bike runs really well. Should I be concerned. I did check other threads on this forum but wanted to ask my own question. Thanks
Blue front header pipe
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normal for the first couple inches that mount to the exhaust port. Other wise major bluing indicates a lean condition... not good. If ran too lean long enough you can melt the tops of the pistons, melt valves, and warp the cylinder and other parts. But seeing as one pipe has a little bluing and the other has none I would think its time to do some carb tuning.
people immediately think that ANY blue on exhaust pipes means a lean condition, and thats just not the case. But yes excessive bluing on pipes is bad and does indicate a lean cylinder. Some guys will never see blue on their pipes because they dont ride the bike hard enough, if you ride the bike and give it a WOT run every now and then its normal to have a little blue color change on the head pipes where they attach to the exhaust port. Or some may never see blue on pipes, because the pipe's wall is thick (*most* stock pies are) others see lots of blue because of cheap thin walled aftermarket pipes, even when a lean condition may not be present. Remember that exhaust gas temps on a gas engine can reach above 1300*F with a perfect A/F ratio during a WOT run. upwards of 1400-1500 with a good A/F ratio and a slightly more loaded WOT run or many WOT runs back to back, and over 1600*F if running high RPM a lot like a racing V8 or an engine that has forced induction like a turbo or supercharger and ran WOT, and at 1600 exhaust pipes start to glow red, 1650+ and they're turning white. So say you chrome the exhaust pipes, at what temp does it start discoloring? I'm not for sure, a lean condition will raise temps quite a bit, but the hotter the temps the more blue you'll see on the pipes.
Nelson racing has lots of videos on youtube of perfect running engines pushing 1000HP and making the headers and turbos glow with no ill affects.
people immediately think that ANY blue on exhaust pipes means a lean condition, and thats just not the case. But yes excessive bluing on pipes is bad and does indicate a lean cylinder. Some guys will never see blue on their pipes because they dont ride the bike hard enough, if you ride the bike and give it a WOT run every now and then its normal to have a little blue color change on the head pipes where they attach to the exhaust port. Or some may never see blue on pipes, because the pipe's wall is thick (*most* stock pies are) others see lots of blue because of cheap thin walled aftermarket pipes, even when a lean condition may not be present. Remember that exhaust gas temps on a gas engine can reach above 1300*F with a perfect A/F ratio during a WOT run. upwards of 1400-1500 with a good A/F ratio and a slightly more loaded WOT run or many WOT runs back to back, and over 1600*F if running high RPM a lot like a racing V8 or an engine that has forced induction like a turbo or supercharger and ran WOT, and at 1600 exhaust pipes start to glow red, 1650+ and they're turning white. So say you chrome the exhaust pipes, at what temp does it start discoloring? I'm not for sure, a lean condition will raise temps quite a bit, but the hotter the temps the more blue you'll see on the pipes.
Nelson racing has lots of videos on youtube of perfect running engines pushing 1000HP and making the headers and turbos glow with no ill affects.
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What these guys said.
Stock? Aftermarket pipes?
Need some pix, please!
If it's the pipe, not the shroud OVER the pipe, it's been hot... but not critical.
If the shroud turned blue: PASS.
That cylinder assembly has been too lean & too hot to be trusted.
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Totally normal. Don't worry about it.
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Good luck!
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I know from personal experience that will happen on new chrome headers or pipes when they aren’t wiped clean of any oils/grease (including from hands) before they are initially heated. The oils become permanently baked in.
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it will happen to any chrome that is heated, but with oils and such on the pipes before they are heated it just shows in the colors from where they were. Like finger prints will show up as a dark blue finger print. But its not permanent, it can be polished off.
Anyways, I looked at both mine and my uncle's factory head pipes off of our Harleys and they had the first 5-6in or so of the pipes blued.
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