When you insert the jigsaw blade, ensuring the blade fits in the roller groove, you can push against the edge of the blade (forward to aft direction) and the yoke/roller assy moves against the spring. Release the blade and it springs forward again, maintaining good contact with the blade's rear edge.
Now, what is the correct way of putting in the blade? Should the blade be just lightly resting against the roller (A)? Or should it be very slightly tensioned against it (by the sprung-loaded mechanism) (B)?
Reason I ask is, if I insert it as in (A), the blade wanders to the left like crazy, even when I use a fence. When I adopt (B), it doesn't. It cuts a nice, straight line. I'm using genuine Makita B 10 saw blades.