Re: Water PSI question
That's pretty low for a new water pump, but it's within what I would consider safe range. What gearcase does your motor have? Do you have a jack plate, and when you take that reading is your motor jacked up? Have you plugged any of the inlet holes in the gear case? This is a relatively common practice on Mercs for anyone with a jack plate. When you raise your engine this keeps the pump from sucking in air and cavitating, and you get a solid flow of water instead of water mixed with air. I have the top 4 holes on my Merc plugged and it runs at about 10 lbs also with the engine down in the water. As long as it doesn't go much lower than this, it should be okay. But, if you don't have a jack plate, and the the top holes aren't plugged, and the gearcase is down in the water, that is LOW for a new pump. It should be in the 25-35lb range. Is your gauge correct? Check it another way, like applying 30lbs of air pressure to the gauge and see if it measures that much.
TG
