Machine adjustments. : eBay Guides

Apply pressure to the armature bar so it makes contact with the top of the coils (the downward stroke position). As you move the armature bar downward, you will notice the contact point is no longer touching the spring. The opening between the contact point and the spring is the gap. The speed of your machine may be changed by adjusting the gap with the contact screw. Closing the gap will result in a faster running machine and opening the gap will cause the machine to reduce speed. If your machine runs sluggish or irregular, you may need to add more tension to your spring. This may be done by loosening the screw that holds the spring to the frame and rotating the spring sideways to the machine, then give it a push, up down, and back up again. Put the spring back into place, line up the points and post and reset the gap as suggested above. Remember to keep the contact points clean with the use of a contact file.