It is very important to keep your serger as clean as possible. That means vacuuming out the lint. Even if you don't have a small attachment, just put the hose near and it will suck out all the lint. You also can use a scrap of fleece to dust out the insides. Change the needles OFTEN. It is less expensive than taking it in for sevice. Be sure to use the right size needles for your machine. Check the manual. If your machine requires lubrication - do it about once a month for a normal amount of use of your serger.
ps - I have made several dusters using scraps of polar fleece. Even use it for my swiffer. Fleece is like a lint magnet. Then throw it in the washing machine etc. and it is ready for use again.