Installing water pressure gauge

[MarkHP]

I am going to put a jackplate (first time I used one) on my 'Stream (Canadian Edition) Vista and as a precaution I would like to install a water pressure gauge. I have a Nissan 90HP and according to Nissan the pressure out of the tellrtale pipe is about 3-5 PSI and too low to be of use. They (Nisaan) also say there is no other port on the motor to install a gauge. Apparantly the motor has a low pressure switch with an alarm but I would feel a lot better with a gauge (kind of like the idiot light in a car that tells you your engine just melted.)

I understand that Nissan can't recommend tapping the motor but maybe someone out there can give me some suggestions on where would be a good place to drill & tap to install the gauge.

[vector mike]

Just put a tee in the piss tube line and run it from there.

[Jeff_G]

On the port side of the motor is a round pressure switch. It is connected to the exhaust water jacket by a small tube. You should be able to tap in there with a tee. Once the motor starts water will flow towards the switch and through the tee towards the water pressure guage you install. Once water pressure is felt it will build up pressure in both the pressure switch and the pressure guage. This should work fine.

I have never installed a pressure guage on a Nissan or Tohatsu but if I did this is where I would try. The water going to the tell tale may be if too little pressure to read properly on that motor.

I would try it without cutting the dash first to make sure all works well and the inclusion of the Tee doesn't upset the alarm pressure switch.

I would also use a 15# guage.

[MarkHP]

Thanks guys. I just found a picture of an optional water pressure gauge in my owners manual (yes sometimes it pays to RTFM!) . This guage shows a 1 Kg/cm(2) scale which, if I calculate right is about 14psi Also in another service manual I found a section discussing 'calibrating' the pressure sensor to turn off at 0.1Kg/cm(2) about 3 psi. From this I deduce that 'normal' pressure should be someware about 5-10 PSI. Unfortunatly I can't try anything until the spring as here in Canada the boat is under about 2ft of snow! How I envy you guys in warmer parts of the world! But when it warms up I will investigate the exhaust connection as Jeff_G suggested.

Happy boating .