Yamaha RX 100, the name still exits in the hearts of automobile enthusiasts and motorcycle lovers even after its production has stopped almost a decade ago. Still many people are ready to spend more than its original price during the time of its manufacturing even today for a well maintained one. Due to strict emission norms, poor scavenging and lack of fuel efficiency the production of 2 stoke engine is banned in many countries but this bike still remains as a legend in everyone's hearts.
If anyone asks whether a 2 stroke engine uses valves many may interrogate that how does a 2 stroke engine has valves and it only uses ports to breathe. The answer is No, even a 2 stroke engine uses valves, especially a performance oriented motorcycle like this legend RX-100. This may be an out dated technology which still many don't know.
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| Reed valve of Yamaha RX-100 |
A reed valve is placed in between engine and carburetor distance piece or spacer. The reed valve acts as one way valve which prevents back flow of charge while the engine is under operation. Due to reed valve the performance is greatly enhanced hence it is used for high performance motorcycles of that time. As we all know that a 2 stroke engine has two strokes namely induction and power stroke. In induction the fresh charge is taken in with the help of it the exhaust gases are scavenged out at the next stroke.
The reed valve is designed in such a way that it is opened for induction process due to lowering of pressure and remains closed automatically during power stroke usually created due to back pressure. Apart from improving performance, this valve also prevents wastage of charge that commonly happens in a 2 stroke engine.
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| Reed valve |
Similarly other valve systems like disc valve, power valve are also used in high performance 2 stroke engines to make it more efficient and to improve its performance. We'll see about power valve and disc valve of 2 stroke engines in the next article.
