10 FE450 Smoke

Hey all,


So I changed mufflers on my 2010 FE450 from the factory krimzon to an fmf ti4. I have noticed that it smokes on start-up, and after riding there will be a nice layer of soot on the tip of the muffler. Any ideas?


I know that its not burning oil because that would be blue smoke...but this smoke is more black, which suggests un-burnt fuel. I am running high octane fuel.


Would putting an iridium spark plug in help?



I had similar symptoms.  Turned out to be a leaking exhaust valve stem seal.

Ok thanks!

I can relax know that I know its not too serious.

Might be a leaky injector. There FI system stays under pressure when shut off, so some fuel might leak out over time if the injector is leaking.

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