Nut on right exhaust heating up? - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 7 (permalink) Old 07-18-2016, 10:45 PM Thread Starter
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Nut on right exhaust heating up?

So I have quite an odd problem. A month ago I had to replace the studs going into the right exhaust manifold after a friend snapped the stud tightening it up. The odd thing is that the nut on the stud heats up and is no longer silver, instead it's like a golden burnt color. Only the forward most nut heats up and the rear one is still silver and nice. After my ride yesterday there was smoke coming from that area. Any idea why the nut is heating up and what would cause the smoke. (The smoke is white)

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post #2 of 7 (permalink) Old 07-19-2016, 06:05 AM
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Uh, that's pretty weird. The only thing that comes to mind (and it's a long shot) is that perhaps one of the bolts was galvanized? Zinc can give off whitish fumes when heated... If you were pulling parts out of a big box store sometimes the stock gets all mixed up and you might have ended up with two different bolt materials? Seems like the texture would have been a give-away, but I have no other ideas.

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post #3 of 7 (permalink) Old 07-19-2016, 08:40 AM
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There also might be a leak there,and the stud and nut are getting hot exhaust heating them up.
If there's smoke there, that might be the problem....

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post #4 of 7 (permalink) Old 07-19-2016, 10:15 AM
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Besides nut material and any coatings, Did you torque nuts to given spec? And then re-tighten later (they do loosen after initial hence manuals directions)
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post #5 of 7 (permalink) Old 07-19-2016, 10:30 AM
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you talking about the acorn nuts, right??

well, them are gonna get hot. the exhaust manifolds are the hottest part on the outside of the engine, probably getting over 500 degrees after its been running a while

Mine have long ago fried off the chrome plating and are just rust covered.

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post #6 of 7 (permalink) Old 07-19-2016, 02:27 PM
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I'm just glad this thread is about motorcycle parts.

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post #7 of 7 (permalink) Old 07-27-2016, 02:57 AM
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the one on the front is getting more oil/fuel than the rear because of the vortex created as it leaves the exhaust.

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