The bobbin thread shows to the front. Does the bobbin or thread tension need adjusted

Bobbin thread showing on top side means the top thread tension is too high or there is too little or no bobbin thread tension.

Be sure the bobbin thread has not escaped the bobbin thread tension spring.

If the bobbin thread is in its tension spring, there will some resistance when you pull the bobbin thread.

Select top thread tension 2, lower presser foot and pull on top thread. Tension should be similar to bobbin thread.

Comment below for further assistance.

Double check that bobbin thread is correctly threaded through its tensioning path.
If it sews fine when sewing a straight line or zig-zag stitch you might have to loosen off the top thread tension a bit, or tighten the bobbin tension.
There is usually a small screw that controls the bobbin tensioner that can be tightened slightly to adjust bobbin thread tension. Do this little bit at a time and test after each adjustment.
Be careful when adjusting, take clear photos before touching anything so that you can put them back where they were if need be. Good luck.

uually your tension should be set between 4and 5 this is a good tension for most fabric

Loosen your top tension. If it is too tight, it will pull the bobbin thread to the top of the fabric. If it continues, then it may have to do with the thread weight you are using in the bobbin or the bobbin tension needs to tightened slightly. HOWEVER, adjusting the bobbin tension is usually a last attempt. It is a sensitive adjustment.

I frequently use a lighter weight thread for quilting and need to adjust the bobbin tension. So, I have a separate bobbin case that is adjusted for that purpose only. Having to adjust the bobbin tension every time one changes the thread weight is a real pain. For most general sewing, the factory set bobbin tension should be sufficient.

Understanding Thread Tension Threads

Am having a difficult time picturing this. Sounds like the upper thread is creating loops under the fabric and the bobbin thread is showing on the top of the fabric.

Make sure to use a brand new needle.

Remove the thread from the machine
ALWAYS raise the presser foot and rethread the upper thread.
Make sure the thread path is correct.

Check that the bobbin is turning the correct direction in the bobbin case and the bobbin thread is threaded through the bobbin tension correctly.

Set the upper tension to the midway point (factory standard), however, this setting may need to be tweaked for your particular machine.

Bring the bobbin to the top of the project Before beginning to stitch.
How and Why to Bring up the Bobbin Thread

Retest--begin sewing slowly.

If the upper thread is still showing on the other side of the fabric, the tension is too loose. If it is pulling the bobbin thread up to the top of the fabric, the upper tension is too tight

OR the bobbin thread tension is too loose. (CAUTION: make only small adjustments to bobbin tension--1/8 of a turn at a time!!! It also helps to mark the screw groove location with magic marker on the bobbin case BEFORE making any changes so you can back it out and return to the original setting.)

Bobbin Tension How and Why Tension is Adjusted

Understanding Bobbin Tension

Understanding Thread Tension Threads

Sewing Lesson 10 How to Fix Tension on Your Sewing Machine

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Remove all the thread from the machine.

Install a brand new needle.

ALWAYS RAISE the presser foot during the threading process and rethread the machine from the beginning. (Check that the upper and bobbin threads are threaded correctly in your machine.)

Set the tension dial to the midway point. This is a factory standard setting but each machine may vary.

Test your machine. The ideal tension is when the upper and bobbin threads meet in the middle of the fabric. If the upper thread is showing on the bobbin side of the fabric, the upper tension is too loose. However, if the bobbin thread is showing on the top of the fabric, the upper tension is too tight.

Tension is not static--whenever you change projects, ie fabric, thread, needle, you may need to test the tension on some scrap project fabric first. Get the tension adjusted before stitching the project.

Make sure you clean and lubricate your machine regularly to keep it operating--consult your owner's manual and use only good quality sewing machine oil (NO 3-in-1, cooking oil, WD-40, or old brown stinky sewing machine oil).

If you are still having issues, take it for service.

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Usually, if there are loose threads under the fabric, it is the top thread that is too loose. Check your sewing sample closely--you can even test with two different color threads to help distinguish which thread is which. Loose top thread will generally be pulled DOWN and show under the fabric. Loose bobbin thread will be pulled UP and show on the top of the fabric. The ideal tension is when both threads MEET in the middle of the fabric.

First, remove the thread from the machine. Install a brand new needle. Always Raise the Presser Foot and thread the upper thread, making certain the thread path is correct.

Check that the bobbin thread is threaded correctly and turning the proper direction in the bobbin case.

Set the upper tension to the midway point and sew a retest. A tweaking of upper tension may be necessary to get it where it should be. Generally, upper tension should make the majority of adjustments needed for tension correction. Bobbin tension is one of the last tension adjustments to make as it is very sensitive and can go awry very quickly.

If, in fact, the bobbin tension is off, the tension skrew on the bobbin case is where the adjustment is made. Before making any bobbin tension adjustments, mark where the skrew slot is located on the bobbin case with a permanent marker. This will allow you to reverse your changes if necessary. Be CAREFUL as TINY changes make HUGE differences in tension. Make only 1/8th turn adjustment, then retest before making another adjustment.

Remember that tension testing and readjustment are a necessity when sewing. The same tension that will work with light weight thread and fine fabric will most likely not work when using heavy thread on drapery fabric. Get comfortable with making tension adjustments to get the ideal tension for each project.

Understanding Thread Tension Threads

Oh You Crafty Gal Sewing Lesson 10 How to Fix Tension on Your Sewing...

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=14&ved=0ahUKEwilg-3t2vHMAhVJDlIKHXnsBWYQFgheMA0&url=http%3A%2F%2Fwww.ca.uky.edu%2FHES%2Ffcs%2FFACTSHTS%2FCT-MMB-213.pdf&usg=AFQjCNE4QlGk1Fvt8K2UGCRCfzMpGS-A2Q&cad=rja

How to Adjust the Tension on Sewing Machine

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if your saying that your bobbin thread is balling up under the platen plate , this is a sure sign that your top thread tension is not correct and there isn't enough tension to pull the bobbin thread up from below

Try loosening the tension for that bobbin

Check the bobbin to be sure the thread is feeding from the spool in the correct direction and through the guides on the side of the bobbin case.

If this is a rotary bobbin (side or front loaded) and not a drop-in (top loaded), you can test the bobbin tension after putting it into the bobbin case. Take hold of the end of the thread, and holding the bobbin case in the flat of the other hand, lift the thread up. If the thread pulls freely from the case, the tension is too loose. If the thread pulls the bobbin case up like a yo-yo and when you give a gentle tug, the thread feeds from the case with a bit of resistance, the tension is okay.

To adjust the tension on a bobbin case, first mark the **** in the screw on the side of the case and the case with a tiny dab of nail polish. This will provide an indication of where you began. Turn the screw to the left to loosen the tension and right to tighten the tension.

Be sure to always thread the machine with the presser foot up.

Set the top thead tension to the number recommended for the type of fabric that is being sewn.

If the problem continues, there is a possibility the timing needs adjusted and this needs to be done by a sewing machine tech.