Hello all! I just picked up a 1984 Crusader day cruiser and excited to enjoy it with my family.  I grew up with a direct drive ski boat but have no experience with a jet. The boat has a 454 BBC and Berkeley Jet 12JC-A.   I'm going through everything and trying to learn all I can while getting it ready to take out. I'v been reading and searching a lot but have a couple questions I cant quite figure out.  I'm trying to figure out the plumbing for the block and water injected exhaust.

What I see ( and could be missing something) is water coming from jet, splitting and having water go into the block, the other split goes to some sort of valve or regulator(which currently has an opening??) and then to the end of the headers. The water leaves the block and then goes to the headers to be injected.

Is this a correct set up? Should there be something regulating amount of water being injected to headers? And any ideas what the valve/regulator with an open end is?  Any help is GREATLY appreciated.  I'll try and post pictures below and a diagram I drew.