Trouble Shooting Bag Closer Bag Making Sewing Machines

General Trouble Shooting for all machines)
First level problems are solved by checking Number 1 to 3

  1. Check threading Needle
  2. Check threading Looper (on double thread machine like the US2200 or Newlong NP3(ii)
  3. In case of a problem with the stitch replace the needle first. This will solve most of you problem
  4. When replacing the needle, make sure it has the correct rotational position (Refer to the manual)
    Everything technical about the Newlong DS-9C
    Read Everything technical about the Newlong DS-9C


  • To keep your machine in shape (if no oil bath) oil it at least once a day before using it. refer to oiling diagrams in the manual of the machine. No Manual? Please contact us
  • For portable Sewing Machines: Use a Spring balancer for easy working and less damages to your machine.
  • When storing the machine put it back in a plastic bag. The machines are always leaking some leftover oil.
  • Use the correct type of oil. If you are not certain which oil please contact us
  • Use the right tools for the project. Tools that do not fit properly can cause extra problems
  • Replace items that wear out (like needles and looper, Feed Dog, Air cylinder (if preset) etc.) on time

If you have questions on a problem or you need to request a repair please contact us


When a Looper is used for a long time, it’s thread eyelet is worn and a groove is produced due to the repeated passing of the thread. It is also subject to damage due to a bent needle hitting on it. Also regular thread jams can wear out the looper. All of these cause thread break. A Worn Looper point is a cause of skipping stitches. If the looper shows one of these signs, replace it with a new one. To replace, Loosen two set screws.

Caution: Use tweezers to remove thread jams from looper.
Facts about a 2-thread looper.
if the looper is not threaded through both loop holes, then the air-stitch is not made. Your bag or material may unravel it selfs. Air stitch of at least 3 cm should be present to make a strong connection.
when using different thread (thinner or thicker) in some cases it is needed to adjust the looper setting.

The Newlong NP-7A machine and how to replace the needle

The Newlong NP-7A (also known as the ‘bag closer  sewing macjine’), is a portable handy piece of equipment for closing bags. This machine assists in sealing bags of grains, animal feeds, fertilizers, potatoes, chemicals etc. The type of these bags may include paper bags of bags for potatoes, woven poly bags of fertilizers, sand bags and construction/paint curtains. This machine is optimized by providing a single thread chain stitch closure that allows  to easily open the bag by simply pulling the thread out.

Replacing the needle for the newlong NP-7A machine

In case you start experiencing issues such as the stitches getting undone when the bag is thrown onto the pallet, it may be an indication that the needle of the NP-7A bag closer needs replacement.

There can be many reasons as to why the needle may have become faulty or damaged. One of the main reasons is that the needle may have hit a hard seed, grain or an object that was inside the bag being stitched. The other reason is that, the needle itself tends to undergo a considerable amount of heat and this may lead to the needle getting bent out of shape or even get warped.

When you are about to replace the needle for the newlong NP-7Amachine, it is mandatory to check on the needle shape and size before considering to replace the previous one. B01002 is the correct needle.

When it comes to fitting the needle to the newlong machine, the needle will have an indentation at the eye of the needle. In order to replace the needle in a correct manner, the concave part (identation) will have to face the looper of the machine.