I bought a brand new 4 lbs battery and it just doesn't have enough power to crank the motor but that is what came stock does anyone have any idea what battery would work thanks.

 

If the Battery is new and in good shape, you have another problem. Bad starter, bad ground, etc.

 

If its having a hard time actually turning the motor over try pulling the plug out and turn it over with no compression . With battery purchase did u charge it after u put the acid in they can be as low 45% chrged capacity.