help setting timing

can someone please help me set the timing on my son's 1986 125 Lt suzuki replaced the piston and rings now cant seam to get the timing right. thanks

You will have a timing mark on your cam,head and cam gear.The one on your head will just be a little point that sticks out.The cam gear will have a notch indented in it,the cam will have a dowel pin that the cam gear sits on.All three must be lined up and be at top dead center with the cam chain on.That should get your timing straight and get you back running

thanks for the help got it up and running. but not sure of the gap for the spark plug .

Try around .22 thous.