KDXRIDER.NET

How does this system work?

Jon.

There's a little gismo in the crankcase that acts like a centrifugal advance and around 6000 rpm the thing twists a shaft that goes up to the right side of the cylinder. this turns another shaft that opens a flapper kind of valve in the big exhaust port, and rotates two smaller drums in the side ports. They also divert the exhaust gas from going into a chamber on the left side to the big exhaust port I think. This is all explained pretty well in the service manual.

And here I was feeding it acorns!

re: 'How does it work?'

It mechanically changes the timing and volume of the exhaust port.

Very much like changing a camshaft (regulation of duration, timing and speed of valve opening) in a 4-stroke engine.

The effect is to alter the breathing characteristics of the engine.

The timing part is probably fairly self evident. The volume part? That has to do with the exhaust pulses in the system, to what RPM the system is tuned to maximize the scavenge/ram effect that makes a 2-stroke work.

There's a reason that a 2-stroke engine's exhaust has converging/diverging cones (expansion chamber) and the 4-stroke engine doesn't. That's part of the scavenge/ram idea, too.

I could go check to make sure it's still there (you can)...but CDave used to have an animation of the system on his site.

KIPS? Cute name for a squirrel.....