Browse Publications Technical Papers 810922
1981-09-01

Improvement of Two-Stroke Engine Performance with the Yamaha Power Valve System (YPVS) 810922

In two-stroke engines, the exhaust port timing has a great effect on engine performance characteristics. If the exhaust port timing can be varied in response to variations in the engine speed, an extensive improvement of performance can be realized.
The Yamaha Power Valve System (YPVS) increases engine output with a valve which operates in the exhaust passage; this valve controls exhaust port timing in response to engine speed, despite the extremely high thermal load encountered in the exhaust passage. This literature deals with the construction and operation principles of YPVS and its effect on the increase of engine output. Also discussed is a series of tests and measurements made on the delivery ratio and trapping efficiency in order to elucidate why engine output is increased.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Preview Document Add to Cart
Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

Modification of Two-Stroke Engine Intake System for Improvements of Fuel Consumption and Performance through the Yamaha Energy Induction System (YEIS)

810923

View Details

TECHNICAL PAPER

Theoretical and Experimental Study of Gas Flow Through Reed Valve in a Two-Stroke Engine

961802

View Details

TECHNICAL PAPER

Evaluation of Reed Valves in High Performance Two-Stroke Engines

942528

View Details

X