My bike requires the choke to start for the first time.......may be some of your issue.
Also, probably need to address the slack in your drive chain. That looks to be a disaster waiting to happen when you do get it started.
Good luck in finding your solution!
Choke to start is normal,
Varies with temperature and air density, however if you have an issue having to where the choke has to stay on in a 2 stroke app your carb could need cleaning, adjustment or has an air leak at the intake gasket at the motor or intake care side.
One way to test if it's fuel related start it and let it run, if the idle slow raises and or idles back down that's an air leak.
Normally, if your carb is gummed up it won't stay running or results in flooding due to a slightly plugged pilot jet or stuck or worn float needle.
If your miles are high enough in a 2 stroke with symptoms of no start or your motor idle gets higher or is unstable you could be in need of crank case bearings when they fail it's not pretty.