Like the Dr said, at low idle, the pump may not push water out the pee hole. In all actuality, the pee hole is there to purge air from the top of block. When ya fire the engine, a quik blip of the throttle should purge the air. After the blip, usually you will see good flow at idle.
As to water temps, no stats cause her to run cool. Most don't see over 160F. At idle, she drops to 120 +/- intake water temp. The alarm threshold is pretty low, this allows the operator to be aware of a partially clogged intake way ahead of possible damage. The older alarms kicked in @ 159F, however Merc updated the sensor b/c some of the alarms would kick for no reason.
Breakin: I understand many have different ways to breakin different engines. I will note, for the last 15 yrs I have worked with nothing but Sport Jets. I strongly suggest following Merc's break in procedure. I have witnessed first hand how quickly the 2.5 will seize the lower two cylinders. WOT high combustion temps, then idle, with no thermostat and the high flow rate of the SJ cooling system will dramatically drop the lower two cylinder temps. This in effect squeezes the pistons. The squeezing may or may not seize the first time, but you'll hear the power head groan.
Now with the 240, you'll have a little leeway b/c the of the extra oil. However, the 200 Opti doesn't offer that luxury. I've seen a very high failure rate of reman Opti due to cold seize. The telltale sign is a scorching hot block, but no overheat alarm. The heat comes from the retracting block squeezing the pistons. When the PH seizes, water flow stops. The block "heat soakes" and gets very, very hot.
