400ex timeing

[81 clark racing]

wel i ordered the curtis sparks adv timeing key an i got it 2day. i was reading the lozey directions if thats what u want to call them haha and it says now that it adv my timeing 6 degress. my stock timeing marks will not be right (tdc) top dead center so i have 2 find the tdc through the spark plug hole. what the hell does that mean how do i do that? any help would be great thanxs guys

[Rancher2005]

tdc means the highest position that the piston can be in the cylinder. by removing the spark plug you would be able to see/feel the location of the piston. i don't know if it is necessary, but find out if tdc has to been found on a particular stroke(compression, exhaust) if you have a compression gauge...use the hose and remove the gauge, put your finger over the gauge and tap the starter switch . when you feel the most air, you will most likely be at tdc of the compression stroke.. hope this helps