[jaguar]

Check out this valve that can replace the reed valve. The inventor hasn't gotten so far as to dyno the results but he swears it gives better power. He just needs to finalize the jetting changes first. I think it's a great idea. www.dragonfly75.com/moto/RRV.html

 

[jaguar]

He said that the increased delivery ratio is causing a huge change needed in the jetting. Now he has a Lectron and is having to make his own metering rod for it, much leaner than anything they make available. Once he gets the jetting straightened out then he will quantify the power increase.

 

[jaguar]

I know the inventor and he showed me a video of him blasting down the street with it, no problem.
From his description it is creating a higher delivery ratio which is causing a need for the jetting to be much leaner (for the same amount of gasoline ingested). The valve itself is very lightweight and is moved back and forth by the air forces applied to it. Reeds can't utilize the end-of-intake-cycle pressure wave to close it right away which means at high RPM it can take 30 degrees of crank rotation to close, allowing intake reversion. This new valve has no reversion.

 

[jaguar]

the spring is soft because the valve easily catches any reversion to rapidly close it. At low RPM the spring closes it before the reversion would happen.
It's a design that can be sized for any engine although the inventor is testing it on his YZ125. He says he tested it up to 13K RPM, no problem.