Bike and pipes are stock. Bought in March of this year w/66xx miles. Currently @ 87xx. Bike seems to run well with no problems. Yesterday I noticed that the left side inner exhaust tip area is blackened with soot(?), while the right is brownish. Any idea what might be causing that? Thanks.

 

Less flow on left side exhaust, so it builds up with soot. The right side just blows it out since it has more pressure

 

Why would that be? I'd think that independent pipes from different cylinders would/should have equal pressure. Something to look into? Thanks.

 

The two pipes are not the same length, so it seems unlikely flow through each muffler is identical. The system is a 2-1-2, in other words the two pipes from the cylinders join together, then split to each muffler and the pipe that goes to the left muffler has two bends in it..

 

...and if you hold your hands at the pipe ends, you'll notice less flow on the left.

as rpms ( and flow) increase, more exhaust will come from the left side as the right side can only flow so much on it's own

- this is not a problem, the design does keep exhaust gas velocity high throught the rpm range

mike

 

Thanks guys. I stopped at a local shop, not dealer, to see what they thought too. I'm a stock is ok with me kinda' guy, but they are trying to sell me an upgraded pipes, breather, and ECM package for $2500. I understand that engines run better when they can breath; don't we all? But......, when dude said $2500, it took my breath away. If it isn't broke, I ain't fixing it.

 

fuel moto

i have a 2011 with 11,5 and just the 3.5 slash down mufflers on and still no discolor on the cans. i have seen bluing on the factory heads. the will get replaced soon with a tuner. i will still fall cheaper than the 2500 quote you heard.