what do these balance shafts do and why do people take them out, please dont say yous search because theres so much stuff to search for and try find answers, id just appreciate a nice simple answer, thanks lads

 

Removing the balance shafts takes some weight out of the car and without the belt etc it is less of a drag on the motor (as minimal as it may be).

With them installed, your motor will run smoother vs without them which causes slightly more vibrations.

As for their exact role, just read this.... http://en.wikipedia.org/wiki/Balance_shaft

 

thanks man ill leave them in so.