I’m just a little confused on the timing. I need to find BTDC, but the online manual and the Clymer manual I have appear to say different things. The Clymer says to turn the engine clockwise until the piston is 6mm (1/4”) below TDC. The factory manual posted here says to turn backwards until the piston is 2mm (1/8” +/-).

Now understand, I am in over my head a little here, but to my mind, turning the rear wheel backward would be taking the timing before TDC and rotating forward would be taking after TDC.

Am I thinking right, or am I just an idiot? And if you need to point out that I’m an idiot, I’m good with it. I’ve been bumbling along for fifty some years now. I only have another forty or so to go.

When facing the flywheel turning it "clockwise" and "backwards" are the same thing.

(with "backwards" defined as opposite of normal flywheel rotation when engine is running)

Thank you, Mark! I’m going to take this thing on a poker run tomorrow!

Well, probably not, but I will be a step closer. 

No quite sure what ya working on but guessing 100cc looking at MX mentioned in previous posts. So all ya need is points just breaking at just under 2mm before top. Just trying to not overcomplicate things. Cigarette paper we used to say. Or us an ohms meter put i won't go into that now. Just cracking free at 1.8mm btdc. 250's have more advance.

Thanks RT325. It appears to be a ‘73 ATMX 125. I will get back to working on it in a little while. For now, I have to run to town, and with gas prices being what they are and with it being such a gorgeous Saturday in NE Oklahoma, I feel that a ride on one of the Harleys is in order.