YPVS
YPVS Yamaha engines, Yamaha Power Valve System: Yamaha engineers realized that by altering the height of the exhaust port they could effectively change the engine power delivery thereby having optimal power and torque across the entire rev range, so it was that the YPVS was born. The valve is of a cylindrical design running across the top of the exhaust port, it is turned by a servo motor controlled from a control box taking information from the CDI (and other locations). The valve is a slightly ovular shape. This changes the height and size of the exhaust port at different engine speeds, maximizing the available power at all rev ranges. It was fitted to all of the later models of the RZ/RD two-stroke road bikes (125, 250 350 and 500 cc), the TZR range, as well as most of the YZ series of motocross bikes. The YPVS is only found on the liquid cooled bikes not air cooled versions. Yamaha have also used a guillotine version in some of their later models such as the TZR250R SPR model. Yamaha DT125R is a street-legal 125cc ENDURO motorbike.
Turbo i motorima - http://en.wikipedia.org/wiki/Turbo#Motorcycle_applications
Evo i kako to radi - http://en.wikipedia.org/wiki/Turbo#Nomenclature
iz čega zaključujemo da su turbo i YPVS dva odvojena univerzuma.
Forumski znalče, ja sam TDR rasturao i čistio YPVS. A ti si sve to pročitao na wikipediji! I pogrešno ukapirao!
Double fail!