Motorcycle Repair: 2003 yamaha 125cc dirt bike, dirt bike, apears

Question
I am putting a new piston in and cannot find the marks to time the valves. The cam sprocket has one mark and apears to match the mark on the head but on the rotor there are 3 marks that I can't match up with any marks on the motor itself. I don't have time to wait for a manual. Can you help?
Thanks

Answer
Terry,

-the valves are usually timed with the
piston at top dead center or "TDC"

-You can check the piston position
through the spark plug hole and
turn the engine until the piston
is at the top of the cylinder.

-On the rotor there should be a single
line or mark. See if it is lining up
with any mark on the engine. This
may help you locate the engine mark.

-Keep the engine at "TDC" and line
up your sprocket mark with the head.

-Install the camchain and sprocket bolts
and double check your marks by turning the
engine slightly back and then forward to the mark.

-Be careful that you don't push any
valves down or they may hit the piston
and bend since the piston is at the top
of it's travel.