setting timing 1984 Honda ATC125M

[Jeff518]

Could someone explain to me how to set the timing on my 1984 Honda ATC125M, I bought a new cylinder head for it and I'm not sure how to do it.Also does anyone know any tricks to change the timing for more performance?If the timing is off, will the valves hit the piston and damage it?
thanks

[Howdy]

1st thing: Welcome to 3WW. We hope you enjoy it.

Now for help: I don't have a book here close by to scan the pages. So I will try off the top of my head.

To set the cam chain:
Get the piston to TDC ( Top Dead Center: this is all the way towards the head ). On the flywheel there is 2 marks. One says "T". That is TDC. The other is "F" for Fire. we will use that one later.

With the motor at TDC, Then have the lobes on the cam pointing towards the piston. On the top cam chain sprocket there is a little "O" stamped besides the one bolt hole. That goes to the top of the motor ( or front on this style motor ). Bolt the cam to the sprocket ( the cam slides into the sprocket on these motors ). adjust the tension on the timing chain and that is done. Be sure to adjust the valves clearances.

To set the Ignition timing: Set the flywheel to the "F" mark and then align the 2 marks on the advancer and the CDI pick up coil at the top. Tighten everything down and install the covers and you should be done.
Howdy