They're extremely beautiful: curved, simple, elegant, ergonomically wonderful, and very Italian. I've been interested in Necchi machines for a few years and until now have avoided the very modern designs of the Mirella, Silvia, and Lydia machines. Try a new needle! Like most problems, try something, test, try something slightly different, test, repeat until successful.
Without a manual this can be difficult! There is a diagram with some threading details for your machine at: There is also a complete manual that is written in Italian but the pictures are much better here: The 2nd most likely problem would be with your needle: dull, bent, chipped point, etc. The first step when experiencing stitching problems is to completely re-thread your machine.
