I have an Imco shorty and a Mercury pressure regulator.

It dumps water at idle and runs around 30-32 PSI running.

I would love to drop the pressure to about 20 or less.

Ken

i have the same on my Playboy boat. Valves that keep it while running at below 30. I only idle around 10. Merc 500 EFIs that make 625+HP

It is a Jabsco brass single stage pump.

Thanks

I first tried one of those regulators and had the same problem .Then I got a weaker spring and the pressure fluctuated real bad. So I ordered a regulator from CP that is adjustable problem solved.

My info was from OEM stock black side ecm 555 and pcm 555 as really thinking the op set up but was not sure what he has nor a stock set up nor what ECM / PCM

Water pressure psi ------- Correct the 700 Sci as Merc spec is 30 psi min at 5200 and MAX 50 psi at 5200 and will add this info the 600 SCi early engine serial numbers were that same as the 700 SCi but later engine serial numbers for the 600 SCi was 30 psi min at 5200 and MAX 42 psi at 5200 --- Merc Spec

Thanks

Ken