The boat shuttle does pull a little more stiff than the round bobbin but should not be that hard. I have several transverse machines and can pull the thread with no problem. You may have a bobbin problem.Does the bobbin turn freely in the shuttle or is it hard to spin? Pull the shuttle thread without pulling the top thread and see if it is still hard to pull. If it is you may have a bobbin that is a little to long for the shuttle. I am guessing now. I have never had this problem.