Scooter troubles

So, I was going home on Friday, and there was this change in sound, and I knew my scooter had something wrong with it. A good friend helped me get it home by putting it in his truck.

So, when I started taking it apart, I found that the spark plug was out of the cylinder.

I took a before picture so that I could attempt to hook up the hoses correctly.

Sorry about no "action" shots, seeing the valves/cam/cam chain and everything is pretty cool. My hands were pretty greasey whenever it would have been a good idea to take a picture.

I adjusted the valve clearance while I was in there. (where do you measure! (between the valve stem and the rocker arms)). I also reset the cam chain adjuster (just to see how it works). My cam chain adjuster is "automatic" because it uses a spring to move a ratcheting piece against the cam chain plate.

I took off the exhaust (pain in the ass!) and just finished painting it with some bbq paint after sanding away (most) of the rust (no more rust for meeeeee (hopefully)).

Interesting to figure out where top dead center is, the spark plug is not at the top of the cylinder, so you can't just stick something (chopstick?) into the hole to figure it out. Turns out there is a marking on a flywheel like piece that has a "T" which is evidently for when you are checking timing stuff. I also verified it by reasoning through the sequence of valve opening/closing.

So, the bad news:

One or both of the following threads are done for:

the sparkplug (easy, just buy a new one)

the sparkplug hole (hard, must tap the hole for larger threads and install inserts)

If the sparkplug hole threads are dead, then I am hoping that I can install a helicoil without taking the engine block out (suggestion is fabric jammed into the cylinder through the hole, some grease to catch chips, then heavily greased tap to also catch chips).

Any of the spark plug work is going to have to wait until after the 4th of July. I might order a battery also, my current one has been dead since at least last summer. Stupid walmart doesn't carry my sparkplug nor my battery.