OMC water psi gauge hookup question

[at100plus]

Is it OK to T off this water line for water psi gauges? It's a 1987 Evinrude 225. 300606 I can't get the starboard side pipe plug out of my exhaust adapters. This line seems to go to the same place just further aft on the adapter. Also curios what the round thingy this line connects to is.

[frederick55]

The round thingy is the water control valve. Below about 2000 RPM water pressure is applied (through the control valve) to diaphragms that pushes the T-stats against their seats. In this position, the T-stats open and close as usual. Above 2000 RPM -- or about -- the control valve (which is moved by the throttle lever) opens and dumps the water pressure off the diaphragms and the whole T-stat assembles are pushed off their seats (By water pressure from the water pump). This allows maximum water flow for maximum cooling I think OMC described it as "Power Boost Cooling". You could "T" in near the elbow coming off the adapter just fine.

[Costa]

The round thingy is what diverts the water through the different hoses based on throttle position, and it is ok to tee where you have shown for your pressure gauge.

Great reply on the cooling system works Frederick55!!!

[at100plus]

The round thingy is the water control valve. Below about 2000 RPM water pressure is applied (through the control valve) to diaphragms that pushes the T-stats against their seats. In this position, the T-stats open and close as usual. Above 2000 RPM -- or about -- the control valve (which is moved by the throttle lever) opens and dumps the water pressure off the diaphragms and the whole T-stat assembles are pushed off their seats (By water pressure from the water pump). This allows maximum water flow for maximum cooling I think OMC described it as "Power Boost Cooling". You could "T" in near the elbow coming off the adapter just fine.

Awesome. Thanks

[rude tim]

On my V8 I drilled and tapped a hole in the block on top of the #1 cylinder. This is the highest point on the engine so it will be the first area to loose water pressure.