Block off plates

[Stichill_imp]

Like Dubs said, this isn’t crankcase ventilation. The reed valves are part of the PAIR system. Per the manual: “The pulse secondary air system introduces filtered air into the exhaust gases in the exhaust port. Fresh air is drawn into the exhaust port by the function of the PAIR control valve.”

If you have a service manual the explanation and diagram is shown in section 1. Is part of the emission controls.

The crankcase breather is also shown in section one. “The engine is equipped with a closed crankcase system to prevent discharging crankcase emissions into the atmosphere. Blow-by gas is returned to the combustion chamber through the air cleaner and throttle body.”

How does the filtered air, going into the camshaft area above the valves / under the valve cover, end up being drawn into the exhaust port from above?