I always had a bit of a love hate relationship with both my Janome coverstitch machines, currently the 2000CPX
@Mocarroll , even though I read all the how to web sites etc., and watched videos. Sometimes it would stitch perfectly but then miss stitches in the middle.
Sometime last year I bought some nice coloured modal jersey (on screen), which turned out to be very light/slippy and not a colour I was that fussed about. To make it up I finished up using some Gutermann Terra plus Mara thread. This time I needed an exact colour. When I did the neck band I turned it over looking for breaks to find it was perfect all the way round. Same with the sleeve and hem stitching. Prior to that I normally used the cheapo threads for overlockers, sometimes using odd Gutermann to match in. Since then I've used all Gutermann on around six or seven projects with success every time. I've always used the correct needles as well.
I still can't believe that this small change made all the difference. I'm really living the dream with it at the moment.