My muffler turned from silver to blackish rainbow color?

J

Jus

Guest
So i just recently assembled my motorized 66cc 80cc bike and its running awesome i think but my muffler turned blackish rainbow color so i think im running to hot??? What u guys think i dont wanna damage my bike or blow a piston or something.
 
Well depending on what your mufflers made of, some do turn color, people usually buy these because of that... But where is it coloring?

P.S. You should make an account :)
 
hmm, second report of this in a week or so - muffler will do this over time, though usually just the header pipe, but I'm wondering if some kits are sending out extra-cheap mufflers lately (or carbs that run too lean)
 
hmm, second report of this in a week or so - muffler will do this over time, though usually just the header pipe, but I'm wondering if some kits are sending out extra-cheap mufflers lately (or carbs that run too lean)
could be an attempt at getting them to meet emissions regulations. good in theory, you burn less fuel you make less pollution. not so good in practice on account of burning less fuel burning more pistons
 
But isn't carb adjustment up to the user?
Or could be cheap carbs don't atomize as well...

Also, a quote from another post similar to this one, he was running 20:1 for oil.
either too hot or too much oil residue sitting in muffler and catching fire

too lean at carb could make it hot, but I'd try 32:1 to see if it stops getting worse

Seems likely. Could you post pictures?
 
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But isn't carb adjustment up to the user?
Or could be cheap carbs don't atomize as well...

Also, a quote from another post similar to this one, he was running 20:1 for oil.


Seems likely. Could you post pictures?
carb adjustment is up to the user, but some people don't bother doing any adjustments from the factory settings.
 
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