Boyesen Reed Valve
The early seventies would see the introduction of the reed valve induction system to the two-stroke trials machines. They were developed by an American company named Boyesen. Eyvind Boyesen was the President and founder of Boyesen, which started a performance revolution in 1972 on a shoestring budget and with a single patent in hand. He used reed induction technology in combination with his patented dual-stage reed to produce instantly stunning results. Motorcycles using Boyesen reeds were consistently outperforming other machines using other modes of intake induction. On trials and in competition the Boyesen name became
equated with superior performance, quality and service.
Since its inception it has set the standard by which all other high performance components and intake systems are judged. For more than thirty years Boyesen has specialised in the design and manufacture of high performance parts to the power sports industry.
The confidence shown by the manufacturer’s research and development partnerships bleeds all the way down to weekend riders looking for that extra performance in the competitive world we live in. Reed valves are used extensively on two-stroke engines and benefit performance immensely, and especially when applied to the trials motorcycle.
Consisting of a flat, thin metal or composite material the reed valve on a motorcycle is designed to allow the fuel mixture to flow in one direction only during the inlet phase.
One of the limiting factors on two-stroke performance is that the induction phase is directly related to the piston movement, and therefore is limited in its duration.
Engines fitted with reed valves restrict the mixture from being ejected back through the inlet port as the piston descends (during primary compression). Although reed valves restrict the flow of incoming mixture their design allows for a greater total amount to be retained in the crankcase and in turn increases performance.
From those early days the applications for Boyesen technology have expanded to include intake products for watercraft, snowmobiles and outboard marine engines. Manufacturing has been — and continues to be — perfected with painstaking precision and care, ensuring the highest quality standards for the ultimate in trouble free performance. Through licensing agreements around the globe, technology designed and patented by Boyesen is built into twostroke engines.
More than two decades and many patents later motorcycle riders and motorsport enthusiasts around the world have turned Boyesen Engineering into a company serving people on six continents. Because of his dual-stage reed innovation Eyvind Boyesen became known as the ‘reed man’ throughout the industry. Never content with ‘good enough’, this Norwegian-born inventor has been obsessed with the desire for continual improvement.
Manmade inventions such as the internal combustion engine could never be said to ‘have arrived’ at perfection. The reason is that human innovation is never static but is always capable of achieving new insights and a better understanding of the dynamic forces of energy and matter. This explains the motivating principle behind the company: to bring creative engineering solutions into the marketplace. But Eyvind Boyesen is not finished yet.
There are a number of plans on his drawing board — prototyped, tested and ready for the right moment to enter the marketplace.
Boyesen Engineering is presently committed to the ongoing development of innovative performance products for the power sports industry, reed induction systems for two-stroke engines, consulting and research services related to two-stroke engine design and the development of technologies and new product lines that will enhance performance in the small engine and recreational marketplace.
This shows the Reed Valve block in position
The man who started the revolution – Eyvind BoyesenThe Boyesen Reed SystemIn this view you can clearly see the application when fitted to the two-stroke motor