My Shark 7133 slowed down while sewing and stopped. The handwheel won't turn at all. I cleaned the bobbin area but it still won't work. The light switches on and the machine motor reves up but the handwheel still won't turn.

You may have already done these steps but when my bobbin stops/starts while filling it I do these steps.
1. Check the thread path to the bobbin area for your machine.
2. Make sure the bobbin is all the way down on the winding spindle.
3. Make sure the bobbin is pushed all the way to the right.
4. Check to make sure the bobbin edges aren't dragging on the guide. I've had this happen and the bobbin will "slip".
If the bobbin is almost full the guide will push it away to keep from over-filling it.
You should be able to control the speed of the bobbin fill the same as you do the sewing feed. Going too fast may also cause the bobbin fill to skip.
Good Sewing!

hmmm...well...is the bobbin clear of any loose threads?

If you have taken out the bobbin case and the raceway the machine should move, if it does not then you have a problem elsewhere and it means a process of elimination to find the problem

If its that hard to turn its needing service. Oiling and lubrication are so important to a smooth running unit. If its that hard to turn the only solution may be to get it into a store for repairs.

Derek

sounds like something is either jammed up or broken inside

Make sure the needle is facing in the correct direction
Put the bobbin in the bobbin case leaving a
2 to 3 tail.
Thread the top of the machine correctly, leaving a 3 to 4 inch
tail after threading the needle.
Hang on to the end of the upper thread and use the handwheel to drop the needle.
continue to turn the handwheel to raise the needle. Pull on the end of the needle thread and a loop of bobbin thread should come up.
make sure there is no lint or loose thread in the bobbin area

Check the manual to be sure the needle is installed correctly, this is usually with the flat side of the shank facing the back of the sewing machine.

Make sure the needle is not bent.

Also, there may be thread tangled in the bobbin area. Open the needle plate and bobbin; clean away any lint or thread that has accumulated there.

If this does not resolve the issue, the machine will need to be serviced/repaired by a sewing machine tech.

Sounds like insufficient tension on the top thread. THIS may be due to variation in the thread itself or incorrect adjustment.

ALSO I recently found out that some bobbins have a metal core that can catch the thread as it goes over. The person recommended using the plastic bobbins that have smooth angled sides.

Usually what we see with these machines is that the hook drive gear behind the bobbin case seizes up check here first and lubricate this area .

just to let you know Euro pro is a off brand and has had many concerns, try oiling the machine in the oil holes provided and also at needle arm, let me know and i will give you more advice