Water Pressure Gauge

[HONKER1]

Went looking on IBOATS for a water pressure gauge kits for my 115hp, 2-stroke. 'o1 Mercury outboard. Found several nice kits to pick from with 2" dials. My motors low side is 2 PSI (IDLE), and the high side is 15 PSI (WOT)
The choice in gauges is 15 PSI (Max) or 30 PSI (Max).
So what would the recommandations be. The 15 Max to cover my motor PSI range. Or should I get the 30 PSI (Max) just in case for some reason I start pumping more pressure then needed? (I don't know if this would even be possible.)

 

[j_martin]

Re: Water Pressure Gauge

The ideal gauge displays normal at mid range. That would be the 30 lb gauge.

Yes, it's possible to go over pressure, and it indicates trouble, like plugged cooling passages. Been there, done that, gauge indication saved the engine.

hope it helps
John

 

[Silvertip]

Re: Water Pressure Gauge

The thought about installing a water pressure gauge is to also install a new water pump/impeller at the same time and then note the idle and wide open throttle pressures. Any deviation down the road indicates the impeller is again in need of service. 2PSI at idle is a tad on the low side (5 - 7 would be more normal) in my view so an impeller change is probably in order anyway.

 

[j_martin]

Re: Water Pressure Gauge

The thought about installing a water pressure gauge is to also install a new water pump/impeller at the same time and then note the idle and wide open throttle pressures. Any deviation down the road indicates the impeller is again in need of service. 2PSI at idle is a tad on the low side (5 - 7 would be more normal) in my view so an impeller change is probably in order anyway.

Depends on the engine, and also the particular gauge. If mine gets off the peg at idle, I'm good to go.

 

[HONKER1]

Re: Water Pressure Gauge

Thanks guys...My gut feeling was a 30# gauge to read the over pressure, but didn't know if a outboard motor water pump was capable of doing that.