Serger frustrations- HELP!

[Gale]

I'm working with Satin on a serger I've had for a while, but only used on a few projects. I've only worked with scraps so far because its taken me literally hours to try to get it to work right, still with no avail. I've tried changing the tension, and the differential feed, but nothing seems to work consistently. "Normal" settings almost work, but again not consistently. My best results come when I'm going slowly, but even that doesn't always work.

So here's my primary problem: I have a long stretch of satin to sew on the bias, and when using all normal settings I'll sew along for a while and it will be nice, but undoubtedly before I'm done with the edge I'm working on the fabric will start to sort of dodge the threads so that the overlock occurs in mid air, or else it will pucker (sometimes a lot, sometimes a little...even on the same setting, worse when I don't lead the fabric with my hands on the front/side corner and the back). It *seems* like it should be a problem with the differential feed, but no matter what I do it only makes it worse.

I'm just about fed up and ready to not bother serging it at all, but I would love to have properly finished seams, especially since I'm entering this in a contest at the next con I attend (in a week, so I'm short on time!) and I know the judge loves to see finished seams. HELP!

Edit: I forgot to mention, I have a 4 thread machine, but I was trying to go for a narrower overlock so I was only using 3 threads. Changed it back to 4 and messed with the tension a bit, it seems to be working better, but still not perfect. I think a big part of it is the fact I'm working on the bias and not the grain. I've got it working well enough for now, but if anyone has any suggestions to make it better PLEASE let me know!

[Katasha]

Normally it means your #3 thread isnt right if your having it loop in mid air, but you have said you tried fixing that. When you thread it do you go from 1-4 or 4-1?.

I only ever really use satin and always surge and it normally is fine. When was the last time you had it serviced? One thing I would try is calling up a local shop who fixes them and explaining the issue, they may even let you bring it in and try something for free.