You may not need a repairman. Bobbin backlash happens when you are moving the machine head fairly quickly and change directions or stop abruptly. The bobbin continues to spin leaving you with a birds nest thread blob on the back. I believe (but am not positive) the magic genie bobbin washers only fit the L class bobbin case. I am not familiar enough with your machine to know if you have an L or M size bobbin case. I swear by magnaglide prewound bobbins by filtec which come in both M and L size. (
www.bobbincentral.com) While Filtec is now wholesale only, if you go to their website you can click "store locator" you can find a retailer near you or find one on line to order them.
I would start with doing a thorough cleaning of your machine in the bobbin race area. Check your bobbin case thoroughly for any lint blobs that may be caught in the tension spring area (run a fine pin under it to dislodge anything) and see if you have an anti backlash spring.
http://thelongarmnetwork.com/anti-backlash-spring You can try ordering one and see if it helps. I found I still got the occasional backlash with it. It is when I use magnaglides that I never have an issue. This site also sells an anti backlash washer (like a magic genie) but only for M class bobbin cases.
These instructions are for backlash issues. If you are having eyelashing which is a different issue all together and is tension related, follow Paper Princess instructions above.
Edited to add, pay attention to your movements when quilting and try to avoid the sudden abrupt change in direction or stops. Try to keep your movements even and at the same speed. This will also help resolve your issues with backlash.