It seems my choke lever has become unattached on my 196cc coleman mini bike. How do I fix it

turn the tick-over down

There is an air leak in the seals somewhere between the carb and the intake manifold. You are getting too much air! ALL of those seals need to be changed, As the paper seals age they develop small cracks that kill the vacuum made by the engine to pull in the gas/air mixture!

It's something related to the clutch.
Key fell out. Clutch failed.
You should be able to see the crankshaft spinning in the clutch housing if it's the key missing.
Probably have to disassemble the clutch to find the problem otherwise.

Hi thermo259, sounds like the high speed adjustment is lean, find the high speed screw and turn it counter clockwise 1 half turn and see if that helps. Should cure it.

Well i had the same Baja mini bike and to be honest with you, you will run into alot more problems with that bike bec they build them so cheap, I and alot of others had 1 thing go after the other on that modle and to me they just aint worth the trouble or money, But check the coil and make sure to

The choke is closed (pushed away from you) to start the bike. When it has warmed up the lever can be pulled back toward you opening the choke back up.

I have a 49cc cateye mini bike it starts idles fina dn every thing but when you ride it it goes fine i can reach around 55 almost 60 with the stock engine but it seems to quit on my after about 15 mabey a little less sometimes and then will not start for about another half hour