From the WR FAQ: Q: How many link pins are between the cam marks for YZ timing? A: If you have a 400 or 426, you will need to rotate the exhaust cam sprocket 1 tooth clockwise at TDC. This will give you 12 pins between the marks, stock is 13. Here's my cams with stock timing. On mine there are 14 pins between cams. What's going on?