Have you looked for the clones threads here?
Info about tensions
Taming the 15 clone tension... well maybe.....
And a lot of valuable info here I hope it’s still here.
Will the Real 15 clone please stand up
And another old fun thread
Janie Doe, the 15 Clone - make over
Make sure it is threaded correctly and make sure the thread goes in the needle the correct direction. Needle goes flat side to the shaft on that machine.