Does anyone know if the decompressoin system can be worked manually? Like with a small lever on the handle bars would that work to ease the starting.

 

yes, just flip the lever UP and it will reset itself every time you try to start it.

It holds a valve open a little so it's easier to spin the engine. and then closes itself.

Hard to believe they actually work esp since you are lowering the compression and that they don't hang open.