water pressure

[num1husker]

Changed out water pump, put in new gauge, cleared out lines and tested, changed thermostats, and poppet valve, I have water out the tattle tale but no pressure.
Does the engine have to be up to temperature to get the pressure, 'm having fuel related issues also so it will only run for 10-15 seconds, I've posted my fuel problem on another thread.
1998 Yamaha vmax 225 hp

Thanks.

jr.

[boats.net]

It wont show water pressure at idle, should have at least 10 psi at wide open throttle.