My ZX12 (a1) is running very rich, which got me looking at the TB air hoses and I see they appear to be set out differently to the manual...

Atmospheric air pressure sensor is linked to the first nipple on the 1st TB (closest to the throttle linkage). I think manual shows this should be capped/open. Not clear. It seems to be there for the California model, to link to fuel gas canister. Looks like the AAPS should have a very short hose to nothing - ie do what it says on the tin.

The vacuum hoses on TB 2&3 are linked correctly, but hose is capped off at a T joint. It looks like this should link to a `vaccum switch valve`, which is missing. This missing valve should then link to 2 hoses going to the `air suction valves`, 2 rectangular valves on the head. On mine, there is a single hose linking these 2 valves, making them redundant.

The Inlet APS appears correctly installed, linking to all 4 TBs.

This has clearly all been done intentionally, but seems very strange to me. Anyone come across this setup on a ZX12 or other bike engine?

Thanks!