Bernina 801 Timing?

I think the timing is off on my Bernina 801 after a major jam. Threads were hung up on the underside in a huge birds nest. Had to apply a lot of pressure to the hand wheel to get the needle out of the work piece so I could cut the threads and clear the machine. Now it just makes a birds nest every time I try to sew with it. What is the proceedure to reset the timing?