often you have the best luck when your bobbin and top thread are the same- much easier to have equal tension.
if you find it is not working for you you could try a bottom line thread- or other bobbin thread (they tend to be 60-70 wt)
i use silk thread alot- love working with silk thread- and my machine loves silk thread- but not all machines behave the same when it comes to threads- best to wind part of a bobbin & give it a try on a practice piece---make sure you use the right needle for your thread/fabric choice- you don't want a big needle when stitching silks....or using silk thread. and silk is VERY STRONG thread! many quilters use silk thread to quilt king sized quilts- it is wonderful for detail quilting....and holds up well.