Necchi overlocker

Thanks for the help in guiding my simple brain to making a new post! Hope
this time I managed it right (hanging my head in shame at the moment) and
will copy the original post here.
'Hi all
Ive had a Necchi 150 overlocker (serger) for 18 months now but for the last
6 months I have been having trouble with it. It sews fine then (for no
apparent reason) skips stitches (the right needle seems to be the problem
there!), the cotton bunches up into the same place on the fabric or the
needles break. I have sent it in for a service and it came back apparently
ok, then a week later started the same old trouble again (I changed no
settings and was using the same fabric throughout the week!). I have tried
adjusting the tension, still no luck. Checked all the threading etc. Could
it be a problem with the needle in the foot plate? I noticed one was bent
and one straight but have no idea if its supposed to be that way.
If it happened all the time I would be less frustrated, but sewing away for
ages with no problem, then out of the blue it going weird is just driving me
mad!!!!
Thanks for your help
Snowy'

Would I need to buy a complete new footplate or be able to change the
needle?

Somestime mine does this when I am using a spool of thread instead of a cone
of thread. It happens when the thread gets caught in the split in the spool
(used to hold the thread when it isn't in use.) My solution is to use a
clean jar lid turned upto hold the spool to keep it from running all over
the place, instead of putting the spool on the spool holder. HTH
Barbara in FL & SC

.. It sews fine then (for no
apparent reason) skips stitches (the right needle seems to be the problem
there!), the cotton bunches up into the same place on the fabric or the
needles break.