[Ando]

Fill the hx with coolant and keep the cap off to add coolant as necessary during initial operation, ok. But:

1. Do i need to put coolant in the overflow tank?

2. Do I open the thru hull valve before or after the engine is running?

3. Prior to installing the FWC system, I had an anti-siphon installed in the exhaust discharge. Is that still a good thing to have or is it no longer necessary?
If it is good to have, does it still go at the high point of the raw water discharge leading to the exhaust or somewhere else?

Thank you all for getting me this far. I do appreciate it.

P.S. I did have a hiccup during the muriatic acid flush. Engine stopped running after taking in ~2.5 gallons of the fresh water/acid mixture and wouldn’t turn back on. All I was thinking was that the mixture that was still in the engine was going to melt it. Ndutton advised me to disengage the water discharge hose and put a garden hose to the coolant input to flush out the mixture from within the engine. Thankfully, I have a hose that fits to the input barb on one end and that has a fitting on the other end that attaches to a garden hose. So the process look less than 10min from when the engine stopped to complete mixture removal.
I then had time to track down the non operating engine. The fuel pump would engage for a second and immediately stop so I removed the + at the starter and the. bypassed the OPSS and then ran the gas line to a clear jug to ensure gas is flowing. It was. Reinstalled the gas line and this time the engine started right up. OPSS is still bypassed for the time being. I left the jug with the gas in it overnight and there is no water in it, which is nice. What can I do to reduce oil pressure so that the OPSS is happy?