What is the recommended PSI for the Blackbird Front Fork?

The Blackbird has 2 adjustments.  There's an air port on top to adjust how much pressure is in the fork, thereby changing the compression.  Firmer for a heavier rider or rougher terrain, softer for lighter or easy going riding.

Max recommended PSI is 150.

The knob on the bottom of the fork is the rebound adjustment, which changes how fast the fork rebounds back.  This setting would be most noticeable in off-road riding.