ok that sound like looper(not cutters) are set incorrectly.this is basic setting,you will need to set it by trial and error if you want good stitching.righthand(upper)looper must move behind l/h(lower)looper in such a way that the point on upper looper fit inside hollow on lower looper when handwheel is turned towards you.at the same time the upper looper point should be approx. 4mmpast l/h needle when handwheel is turned further as the needle bar comes down.also at same time r/h needle should be at this time be just above top edge of looper.moving handwheel further the lower looper should be approx. 4mm left of l/h needle on return stroke while point of lower looper be approx. 1mm above l/h needle eye.the basic idea is to catch the needle cotton with lower looper when looper is moving towards right while upper looper form chain by crossing looper action and pulling needle cotton towards and over material.good luck !!
johan
July 2013