Exhaust water flow

[Rick.johnson]

Hi Guys
I have a 1987 Hunter 40 legend
With a 4jhe Yanmar engine

Question then I have it running I cant tell if I am getting any good
water flow thru the sea water pump to aid in keeping her cool
for the exhaust water an engine exhaust blows out under the boat waterline

I Am thinking of putting in a small visual flow meter by the Kingston cock or just before the sea water pump inlet in the hose there Now I use a therm laser to take the temp of the engine an she seem always at about 170 deg f

Is there enough flow to use a flow meter

Please Advise Thank Rick

 

[HMT2]

I had one of these on my boat. Super easy to install I loved it! Buy the kit with the alarm.

Cooling Water Flow : AQUALARM, Warning Systems For Land And Sea

AQUALARM : Cooling Water Flow - Security, General Alarm Cooling Water Flow Automatic Sys Monitor Exhaust, Engine Monitors&Sensors Bilge Alarms & Switches Watch Alarm , Aerator, Alarm Mat Fire and Smoke Alarms Audible / Visual Alarms Hose to Barb Adapters Custom Panels Replacement Parts Cellular...

aqualarm.net

 

[Rick.johnson]

Hay Thank Mike that would take care of my problem
To make sure she stays cool

Will get on an give it a try an mount the alarm up in the cock pit area

 

[jssailem]

Lots of options:

• Stick a pole down in the water near the exhaust. Is it being knocked about? Probably you have water flow.
• Put a temp sensor on the exhaust pipe aft of the water injection elbow.
• Use a IR sensor and target the exhaust manifold, then the exhaust hose.
• Get in the dinghy and scoot around to the exhaust port and stick your hand down near the port. You can get a read on temp and pressure.
• Monitor the engine temp. If it is not steady at 170 then you may have a problem.

 

[JoeWhite]

To test the water flow, close the raw water intake thru hull valve, disconnect the hose from the output of the water filter and insert into a 5 gallon bucket of fresh water and see how long it takes for the water to empty when engine is running. Keep a shore water hose handy and fill the bucket before all the water is emptied. I would think it would take about 2 minuites for the bucket to go low. This is best done with 2 people, one at the Helm ready to stop the engine.
If the water temp on the engine is lower than what you are used to, then there may be a clogged intake.
If slow water draw, then check the impeller in raw water pump.
To avoid forgetting to open the raw water intake, I place my engine keys on the valve handle. I have also added a magnet on the handle with a magnetic switch and added a buzzer at the captain's instument display. When key is turned and if the handle is not open the buzzer will sound.

 

[Don S/V ILLusion]

Was the 40 designed to have the engine exhaust below the WL.?

That seems like either a bad design or an overloaded stern. Regardless, since all kinds of bad things can happen unless this is changed, I’d suggest you do that first.

 

[Rick.johnson]

Yes she was designed that way from Hunter

I like the first Answre using the in line electric water flow meter

 

[dlochner]

I had one of these on my boat. Super easy to install I loved it! Buy the kit with the alarm.

Cooling Water Flow : AQUALARM, Warning Systems For Land And Sea

AQUALARM : Cooling Water Flow - Security, General Alarm Cooling Water Flow Automatic Sys Monitor Exhaust, Engine Monitors&Sensors Bilge Alarms & Switches Watch Alarm , Aerator, Alarm Mat Fire and Smoke Alarms Audible / Visual Alarms Hose to Barb Adapters Custom Panels Replacement Parts Cellular...

aqualarm.net

I just learned about this device and will use it on a boat I am refitting.

 

[Ralph Johnstone]

Here's mine in position for a Yanmar 2GM20F :

 

[Ralph Johnstone]

Was the 40 designed to have the engine exhaust below the WL.?

No rhyme Nor reason. Some did, some dinna.

My boat (H-310) and another H-310 came on the same flatbed from the Hunter factory in Fla. Mine has the exhaust below the water line :

The other H-310 had the exhaust roughly in the same location but on the side of the hull and well abover the water line.

The only way you can tell if the engine is running is from the hull vibration. No external sound. Ideal for sneaking up on kayakers.

 

[Tally Ho]

My Hunter 280 also had the exhaust exit below the waterline.

I could hear a difference in the tone of the engine exhaust when I forgot to open the cooling water thru hull.

Would be harder to notice a gradual reduction in cooling water flow though.

Greg