Bernina 801 Sport

I experienced the same issue with an older Pfaff, especially when I sew very fast. I fashioned a piece of tape to close the opening in the take-up lever...no more jumping thread! You can probably use other items (like hot glue) to close the opening. A cheap fix that works!

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Hi Jim&Bev, The link below in a 23 page user manual for a Bernina 801 Sewing Machine, I hope this helps.......CHEERS..
Bernina 801 Owner Manual

V-Belt replacement 801/801 Up Machines

Only the belt cover needs to be removed for this belt change. This is done by removing the three screws on the end/belt cover. Loosen the 5mm Allen socket head screw below the step pulley to relieve the belt tension. Remove the lower motor belt. Lift the step pulley and slide off the hand-wheel, (assuming that you have already removed the release knob and clutch ring).



Additional top cover removals 807/801 Minimatic machines

Early 807 machines had two expansion nipples in the top cover that fit into receptor holes in the upper arm frame. Simply pull up the top cover.

Very late models may have a push button latch mechanism, same as on the 801 machines except those fitted with carrying handles, i.e. 801 Sport, 810 machines.

This is accessed by opening the light cover and finding an aluminum knob in the upper left hand corner of the upper arm frame. Push this in and the cover will release. Lift off the top cover.

All the CB machines are threaded in a similar way. Here's a Youtube video illustrating the process on a 1008. Plenty of other examples on Youtube too.

You will probably find the information that you need here: BERNINA Startseite Herzogenbuchsee Info BERNINA Service Tipps Lenco...

There's a great deal of information about the mechanical Berninas but the site is in German. It will be worth your perseverance though.

On the bobbin casing is a screw to adjust bobbin tension when upper tension will not solve the problem. Check your manual for location of the screw.

If handwheel is difficult to turn manually, it most likely needs cleaning and oiling.

clean under the needle plate
clean the bobbin area for loose threads or lint

if this doesn't make the noise stop then it may need to be serviced

There is a small knob on the lower part of the main body under the stitch length lever. This controls the feed dog up or down. Make sure that it turns easily and fully to both positions. If it does and your problem persists, the feed dog height adjusting point is probably loose. A knowledgeable repair person needs to look at it. It is not a difficult repair, but several approaches need to be taken.

You can oil any two metal parts that move togeather or through each other. Do not oil bearings and do not oil gears. Do not use 3 in 1 oil or WD-40. Use regular sewing machine oil.
801's were made from 1979 - 1982. The way Bernina dated these on the machine is by the serial number. Your number would probably start with a 0 or a 1. 1970 is a 0, 1971 is 01, 1980 is 1, 1981 is 11, 1990 is 2, 1991 is 21 etc. etc.
Rick