Ignition Timing

[ozark]

Is this the right T mark for top dead center when reinstalling the cam?

This is where it was with the cam aligned when I took it apart.

The engine starts in both positions but makes a heck of alot of racket in the second photo. Any advice on this.
I'm confused!

[Doug in San Diego]

there is a good picture here

scootdawg.proboards.com/index.cgi?board=talk&action=display&thread=23946

looks like it should line up with the T

Now I think Of it, did mine line up perfectly with the T ? I wonder

[numbski]

Mine is lined up between the arrow and the T, at the line. But then, I just put all of mine back together - and if you look at my other live thread, you'll see that my success hasn't exactly been immediate.

If it's making racket, it's wrong. You're making contact with your valves and running the risk of damaging them. Roll it back to your first photo. Inspect for valve and piston damage if you have time to do so.

Ozark, if you give me a buzz I might have time to swing by later and give you a hand.

[ozark]

Seems I put to much thought into it. The timing was right the first time. But still having a problem with the scooter missing at high rpms and the tach needle bounces. Starts and idles fine and light throttle ok. I'm guessing a loose connection but wondering if the carb diaphragm may be the culprit.

[indy50]

I've seen the tdc mark vary a little between engines
I usually rotate engine with the head off until the piston reaches the highest point in the cylinder, then mark the flywheel with a sharpie
On 1 of mine tdc is acouple mm's from the tip of the arrow towards the T
On another it is closer to the T than the arrow