Several months ago I tried to install a water pressure gauge on my 2018 Yamaha F150 outboard and found a couple of posts of guys showing where to plug the hose in on the engine side. It did not work. I contacted Yamaha and was told that the motor runs with "high volume and low pressure" that a gauge would not show any water pressure and I repeated that claim to other guys asking about installing a water pressure gauge on their Yamaha outboard. After some further investigation I found the port, thru an adapter, to connect the hose to. It worked and it works fine. Since I was under the impression that I'm dealing with low water pressure I bought a gauge that reads 0 to 15. The gauge starts reading just above idle and pegs out before half throttle which is fine with me. If I would do it again I would get a gauge that reads up to 30 or 35psi. Overall I'm happy that I don't have to look for the pisser each time I start the motor. I'm posting this in hopes it may help someone in the future.
