Husqvarna weed wacker

[D2hornets58]

I have a Husqvarna weed wacker that i bought last year. When i pull the pull rope to start it the pull rope just pulls very easily and does not turn the engine. I believe I need a part but i don`t know what its called or where I would get it. Someone told me that on weed wackers these are plastic and often wear out quickly. what is this part and where could i buy one?
Thanks

 

[Ganall]

Is it a piston? It sounds like a piston.

 

[D2hornets58]

Is it a piston? It sounds like a piston.

i was thinking something in the starting mecanism. It seems like when I pull the rope it just does not engage.

 

[Parkmower]

It's like a spring loaded plastic tab that engages the flywheel. I don't know it's proper name.

 

[D2hornets58]

It's like a spring loaded plastic tab that engages the flywheel. I don't know it's proper name.

Do you know where I could buy one. I have found some websites that sell parts but not sure what to get.