Cant get my 50cc scooter to fire up-no spark. any

Engines only need three things to run.

Fuel in the correct amounts
A Spark at the right time
Compression

Check the compression. Make sure the fuel is reaching the spark plug.

being a 50cc engine it should have only 1 piston
If it is a 2 stroke , it will fire every time the piston comes to tdc
if it is a 4 stroke it has to have a timing point that excites the ignition system for every 4th stroke tdc
if the exciter receives a signal to fire the plug at the wrong time , it is getting that signal from a fault or incorrect timing
that fault can be
loose wire/s,worn unit that controls the timing ( distributor fault), loose flywheel , flywheel touching coil,incorrect timing (180 degrees out ) stator loose ,rotor loose,faulty crank position sensor
it is good practice to have a workshop manual on hand and if you don't have one go google and type in --workshop manual for 50 cc tao scooter--and see if there is a pdf version in english to download

Change the plug if spark still faint then check plug leads & coil.

Scooter Troubleshooting Scooter won start All about Scooters

http://scootermasters.com/manuals/02-05%20Zuma%20SM.pdf

https://www.youtube.com/watch?v=PBpS_KTQgN0

Hopefully, one of these links will help.

with the spark plug out and the valve cover removed; place a screwdriver into the spark plug hole; turn the crankshaft until the valves are all the way up and, not moving as the piston just starts to go down in both directions; (use the screwdriver to see this) this is TDC or, top dead center now; you should see symbols on the faces of the cam gear and, the crank gear and, two places on the chain; line up the chain symbols with the gear symbols chain symbols facing out and, install the chain.
by the way they make a kit for stripped sparkplug holes an auto parts store will have it in case you need one again.

have you checked that the spark plug is tight and that the ht lead is on the spark plug?

check the battery coil wire

The ignition timing may have been disturbed,or if it is equipped with a carburettor,the mixture setting may have been disturbed,or the carb.jet may be blocked by dirt in the fuel or the spark plug may be faulty .get all these checked first .