I would like to hook up an engine temperature guage and either a pressure guage to the outlet side of my cooling line or a flow guage to the inlet side of my cooling line. My engine is mounted below deck and I run shallow sandy areas. I haven't had an issue in the past but I always worry about loosing cooling. Can anyone help in telling me what all I would need fittings, sensor sending unit, guage. I looked around it seems I would have to piece one together and I don't know enough about it to part by part order what I need.
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after market temperature and flow guages on inboard jet
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CedarRiverScooter
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How about a pee line so you can visually verify cooling is working (like Mercs). Could be where you can see it from driver's seat.
PSG-1
Well-known member
Amk, get an outboard pressure gauge. Use a "T" fitting in your cooling line going from the pump to the engine, and then hook the tubing for the pressure gauge to that.
If you are using an inline strainer, be sure to put the "T" after the strainer, and not before. Reason being, if the strainer clogs with the T on its inlet side, the gauge will continue to read pressure, even though no water is flowing to your engine. With the T installed on the outlet side, if the strainer clogs, you will see an instant drop in pressure.
This is the setup that I use in my boat. At 7K RPM with my FXHO (4,500 RPM for a non-reduction geared PWC engine) I am getting about 7-10 PSI. If I see higher readings, it means an obstruction beyond the strainer, or a kinked hose. Again, a drop in pressure indicates a clogged strainer, or clogged cooling line between the pump and strainer.
If you are using an inline strainer, be sure to put the "T" after the strainer, and not before. Reason being, if the strainer clogs with the T on its inlet side, the gauge will continue to read pressure, even though no water is flowing to your engine. With the T installed on the outlet side, if the strainer clogs, you will see an instant drop in pressure.
This is the setup that I use in my boat. At 7K RPM with my FXHO (4,500 RPM for a non-reduction geared PWC engine) I am getting about 7-10 PSI. If I see higher readings, it means an obstruction beyond the strainer, or a kinked hose. Again, a drop in pressure indicates a clogged strainer, or clogged cooling line between the pump and strainer.
I don't use a strainer maybe I should but I haven't had an issue yet I know sand and small gravel will clog it instantly but for the most part sand liquidized will flow through the system I would just like to put a temp sensor on the outlet and a pressure guage on the inlet to track it. I do have a pee line but I don't trust it will indicate partial clog or engine temperature.
PSG-1
Well-known member
You should consider using a strainer. It's a lot easier to unclog one of those than it is to try unclogging the cooling system of the engine. Liquidized sand will pass through, but it only takes a few larger pieces of ground-up shells or rocks to play havoc on your engine.
Like I said, the OB pressure gage is your best bet if you want an instantaneous reading of what's happening with the cooling system. With a temp gage, or a temp warning buzzer (I had both of these on my old 2 stroke engine) you won't know the engine is not getting flow until it's too late and you've got an overheat.
But if you do want to install a temp gage, water from the discharge outlet won't work as efficiently as mounting it to the exhaust manifold. When I did it on my 2 stroke, I made a large internal-threaded fitting out of round aluminum, and welded it to the manifold, so the temp sending unit would screw into that.
Hope this info helps.
Like I said, the OB pressure gage is your best bet if you want an instantaneous reading of what's happening with the cooling system. With a temp gage, or a temp warning buzzer (I had both of these on my old 2 stroke engine) you won't know the engine is not getting flow until it's too late and you've got an overheat.
But if you do want to install a temp gage, water from the discharge outlet won't work as efficiently as mounting it to the exhaust manifold. When I did it on my 2 stroke, I made a large internal-threaded fitting out of round aluminum, and welded it to the manifold, so the temp sending unit would screw into that.
Hope this info helps.
okavango
Well-known member
Hi PSGPSG-1 said:
I'm definitely going to follow your advice and install a pressure gauge. What max pressure reading do you get, would a 30 PSI fuel scale gauge be sufficient?
PSG-1
Well-known member
At 10,000 RPM (roughly 7,000 for non-reduction geared engines) I'm getting about 15 PSI, on 1/2" cooling hose, with a 155mm Yamaha pump.
