See if this works with your machine
Janome Bobbin Thread. 100% Polyester, #90 weight, 328 yards (300 meters). Pack of 5.
This is thinner then regular thread, which is 50/2.
While these pre-wound bobbins are meant for Embroidery, they can be used with sewing only machines. Sewists have used both the 90w and 60w for Decorative stitching and Quilters have indicated that stitches made with 60w bobbin thread sink better into the fabric and lay better in their quilts.
Part Number: J209 (Black Thread) and 200921781 (White Thread)
Guaranteed to fit because it is a part.