What does Yamaha YPVS stand for?
What does Yamaha YPVS stand for?
Yamaha Power Valve System
Yamaha Power Valve System (YPVS)
How does Yamaha YPVS work?
The YPVS employs a spiral shaped valve located on the top of the cylinder’s exhaust port. In this way the valve moves upward and downward out of the exhaust port. This means the exhaust timing is constantly adjusted in accordance with the rpm level, thus giving more effective timing over the entire speed range.
What is a 2 stroke power valve?
A 2-stroke power valve is nothing more than a piece of metal slid into the engine’s exhaust port. Its primary function is to regulate the size of the exhaust port, thus enabling the engine to deliver controlled power throughout the rev range.
How many valves does a 2 stroke engine have?
Standard uniflow-scavenged two-strokes have intake ports that are controlled by the piston and four valves in the cylinder head that are used to manage the exhaust flow.
What is the purpose of a reed valve?
Reed valves are a type of check valve which restrict the flow of fluids to a single direction, opening and closing under changing pressure on each face. Modern versions often consist of flexible metal or composite materials (fiberglass or carbon fiber).
What is Kawasaki KIPS?
Kawasaki uses a power-valve system called KIPS (Kawasaki Integrated Power Valve System) on their two-stroke bikes. The KIPS utilizes both alterations in port height, closing of the secondary port ducting, and a resonant chamber. KIPS is operated by a mechanical governor on single cylinder machines.
Why are 2 strokes banned?
Carbureted and electronic-injection two-stroke engines are considered high-emission engines. A carbureted two-stroke engine can emit up to 25-30 percent of its fuel unburned into the water or atmosphere, which is why high-emission engines are prohibited on some lakes.
What does a Yamaha power valve do?
YPVS-Yamaha Power Valve System This changes the height and size of the exhaust port at different engine speeds, maximizing the available power at all rev ranges, opening up firstly at 3k rpm for low end power, gradually in between 3-6k, fully opening at 6k rpm for maximum power, on most 125cc.
Why are 2-stroke engines banned?
