PM 300 water pressure

[apexfx]

i have a 300 promax and my buddy has a 300 promax,same year,mine runs 8psi at 70 mph and his runs at 25 psi at 70 mph ?

[Wingnut0302]

I'm running at 10psi at best myself at full speed (around 80) and havent seen the temp go above half...Im looking forward to a fix if there is one.

[amityray]

I got this straight out of the manual.
Water pressure Check:
1) Water pressure at idle in Neutral is 2-5 psi.

2)Water pressure should increase, then drop to 4-6psi. prior to 2500rpm ( due to the poppet valve opening at 2500rpm)

3) At 2500rpm water should not exceed 12psi.

4)Static test (boat stationary - operate in foward gear with a cut down propeller) at 5000rpm or above. Water is above 8-10 psi.

I don't know how you would do step 4. But my 300pm has never had more then 10 - 12 psi. I've never had any cooling problems. I've read many times that these motors have high volume - low pressure. If its not getting hot I wouldn't worry.

[apexfx]

i have a manuel, where did you find that

[amityray]

General Information....Page 1-21. Water pressure check.

[rchevelle71]

Sounds like his poppet is not opening.

[amityray]

I don't think there's anything wrong with his motor. This topic has been brought up a few times in the past. Now his friends motor running 25psi could have an issue.

[Propster]

One of my motors went form 10-12 psi to 25 psi. Stuck poppet valve. Un-stuck the valve, now back at 10-12 psi.