2014 wr450f with GYTR exhaust tip

I've put this tip on, and removed the stock exhaust tip.  The spark arresting screen is still in the exhaust and can be seen with a flashlight when shined up the pipe.


The USFS in Washington can be a pain. Can anyone tell me where or what marking on the stock exhaust indicate it's USFS approved?  I may be suffering from man's disease (can't find it because it's right in front of me).


I can just see it now...after they inspect the DOT stamp in the sidewalls, they'll give me a hard time because THEY don't know what any of the markingsP1030161.JPG mean, either.P1030160.JPG



If they can stick a rod down the pipe more than 5", they will consider it not to be spark arresseted

Did that happen to you?

You are good as long as you don't remove the removable screen spark type arrestor. YMS400B is the USFS description of the muffler. The screen spark arrestor isn't in the tip of the muffler anyway, it's in the body so you didn't affect anything. They will prob you anyway even with the stamp on the side because it is a removable part.

Tape measure goes in 7" before bottoming out on the screen.

You are WAY overthinking this.  There is no regulation that dictates the dimensions or length or whatever you want to call it.  The probe they use is usually the length of the entire muffler.  If it goes in far enough to go through the entire muffler without stopping they will consider it to not have a spark arrestor.  This cover about 100% of the mufflers with the screen type spark arrestors.  You are good to go :ride:

Edited by KennyMc

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