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Mercury 150 2 stroke water pressure?

Bravo12

New member
I have a 2000 Mercury 150 2 stroke carb motor that I just had the power head rebuilt. At that time I installed a new water pump along with a new poppet valve. I also installed a water pressure gauge and temp gauge. The first time out I noticed that the water pressure is at around 3psi at idle and goes up to around 7-8 at around 1800 RPM. If I push it on up faster to around 3000 RPM the pressure will fall to around 5psi. I did not run it above 3000 RPM because of breaking in the motor. The temp did not go above around 160 or so and would cool off some at the higher RPM. Is this drop in pressure due to the poppet valve opening and is this low at those RPM? The temp gauge I installed is the kind that has the sender attached against the head and I have it mounted close to the sensor for the alarm on the starboard head. I have the water pressure gauge connected at the bottom starboard side of the motor where a small grey line was that I was told was for this purpose. I am concerned about the pressure and wonder what will happen when I can run it on up to a higher RPM. Does this seem normal? Any thoughts and help will be appreciated.
 
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