Is the auto decompression for motor suppose to be lose if you work it by hand you can shake mine and it rattles is this normal?

 

I just replaced my cam and what a difference, (see post "2006 Rubicon Engine Knock). The decompression cam mechanism has a small spring that pushes the lobe up and locked on the compression stroke releasing compression while starting. When the engine starts a counter weight and centrifical force unlocks it. My decompression cam would not unlock and would not release. Changed it and knock is gone and the power is back.

If you get a new cam you can compare it's functionality to make sense of how it is properly supposed to work. Until then I was not sure. You will definitely hear a upper engine knock as a result of a bad decompression cam. Mine would go away for the most part when the engine was warmed up.

 

Thanks for the reply just ordered new cam yesterday

 

Something I should mention... When you assemble your new cam and hand turn the engine with the rip cord you will hear a click on the compression stroke somewhere. Don't worry about it - it's the decompression cam disengaging and is normal. When you start it normally you do not hear this because it is drowned out by the starter noise. I was concerned I had something assembled it wrong and tore it down to discovered the above sound. Fired it up once put back together and all she sounded good.