Q1: what [electrically operated] water pressure gauge [with a remote sender] is now used by Boston Whaler [on their 170 MONTAUK boats]?
I plan to replace the present engine [2002 Mercury 90-HP two-stroke-power-engine] water pressure gauge with an [electrically-operated] gauge [that connects to a remote] sender.
I plan to track down [a new electrically operated water pressure gauge that uses a remote sender whose visual appearance] looks correct [that is, matching the appearance of the existing engine gauges on a 2002 170 MONTAUK].
Moderator's note: this discussion thread is actually located in the SMALL BOAT ELECTRICAL forum.]
Electrically Operated Water Pressure Gauge Now Used by Boston Whaler
Re: Electrically Operated Water Pressure Gauge Now Used by Boston Whaler
Q1: what is your basis for assuming that the engine water pressure gauge now used by Boston Whaler has changed to be an electrical gauge which is controlled by a remote sensor?
I do not believe that Boston Whaler has sold a Mercury 90-HP two-stroke-power-cycle engine in perhaps 15 years as part of any pre-rigged boat-engine combination. The typical 90-HP outboard engine using two-stroke-power-cycle technology has always used a water pressure gauge that connects via a water tube to the engine water pressure measuring outlet.
If you really want to make the water pressure measurement more complicated, you can get a pressure transducer and connect it to a dial pointer gauge that is matched to the resistance values of the pressure transducer. But that seem like making something simple into something complicated. In order for the calibration to be stable, the voltage operating the gauge will need to be carefully regulated. You will need to add a voltage regulator to the power circuit, or accept the variations in calibration.
Typically today, engines using NMEA-2000 protocol to supply data about the engine to display devices will--by necessity--use a pressure transducer to measure the engine cooling water pressure. Typically the engine's electronics module senses the resistance of the pressure transducer by passing some current through the resistance. The electrical current value is then converted into a water pressure reading by using some sort of algorithm that is matched to the particular transducer being used.
A c.2002 Mercury 90-HP two-stroke-power-cycle engine will NOT have a NMEA-2000 interface.
Good luck in your new project.
I do not believe that Boston Whaler has sold a Mercury 90-HP two-stroke-power-cycle engine in perhaps 15 years as part of any pre-rigged boat-engine combination. The typical 90-HP outboard engine using two-stroke-power-cycle technology has always used a water pressure gauge that connects via a water tube to the engine water pressure measuring outlet.
If you really want to make the water pressure measurement more complicated, you can get a pressure transducer and connect it to a dial pointer gauge that is matched to the resistance values of the pressure transducer. But that seem like making something simple into something complicated. In order for the calibration to be stable, the voltage operating the gauge will need to be carefully regulated. You will need to add a voltage regulator to the power circuit, or accept the variations in calibration.
Typically today, engines using NMEA-2000 protocol to supply data about the engine to display devices will--by necessity--use a pressure transducer to measure the engine cooling water pressure. Typically the engine's electronics module senses the resistance of the pressure transducer by passing some current through the resistance. The electrical current value is then converted into a water pressure reading by using some sort of algorithm that is matched to the particular transducer being used.
A c.2002 Mercury 90-HP two-stroke-power-cycle engine will NOT have a NMEA-2000 interface.
Good luck in your new project.