I am rebuilding my 150hp V6 Mariner and as I go I am looking for causes of the broken ring on No. 2. I have noticed that the diaphram in the poppit valve was perished and had a hole and there was a large amount of corrosion and salt behind it. The build up was such that the valve could not move at all. What happens when this valve cannot function. Would water pressure be reduced and cause the motor to overheat. Thanks.
