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Can some one explain the stock exhaust to me?? This is what yamaha canada writes:
All new, mid ship design 4 into 2 into 1 exhaust system features lightweight titanium header pipes and muffler. This new design maximizes power, reduces weight, it also centralizes mass and lowers the centre of gravity for fast, light, agile handling. This system also contains dual 3-way honeycomb catalyzers which reduce harmful CO and HC exhaust emissions.
New exhaust valve device is located in the under engine chamber and it features two separate exhaust flow routes depending on rpm. By controlling the exhaust routing at selected rpm ranges, it has been possible to build a compact muffler that achieves both outstanding power output and torque characteristics while still providing sufficient silencing performance.
Yamaha's EXUP System (Yamaha's Exhaust Ultimate Power Valve) controls the exhaust pressure waves for optimum intake and exhaust efficiency. It also helps prevent the "blow back" phenomenon caused by valve overlap and helps reduces "flat spots" in the power band while reducing emissions at the same time.

When I watched the sportbiketrackgear.com video about removing the stock exhaust and servo with cables it appears that the flapper in the exhaust end pipe right before the slip on is the only valve moving. I though there was a controlled valve in the big canister like the EXUP valves from say a 99 R1 but there isn't?! What's actually going on in the big can and what is the exup?
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