So how do you know if the strainer is full to the top? Can you hear it? Is there a certain amount of water I should see coming from exhaust? I'm new to all of this so sorry for the ignorance. I disconnected the hose that connects the outdrive to the motor and put the water hose there and the motor didn't overheat. It was around 180 at idle.
Here's my two cents.
Check the cap gasket that's over the strainer, and make sure that it seals correctly, and don't worry about the water level in strainer for now.
When we trouble shoot a cooling issue, we should look at the entire system, and not focus mainly on a thermostat or pump impeller right off the bat..... although these are suspects.
Start at the drive area where the sea water first enters.
On your drive, there is an O-ring seal at the lower most end of the pivot tube where the tube joins the lower unit housing.
This is not an easy O-ring to access, but it needs to be in good condition.
At the upper end of the pivot tube, is a pivot tube bushing, and a water neck fitting.
The water neck fittings are prone to corrosion issues.
The fix is a new water neck fitting and the special beaded gasket underneath it..... bead facing downwards.
If you have not replaced the water neck fitting, it's time to do so.
However, if the upper pivot tube bushing is worn, the play between the pivot tube and suspension fork will prevent the new beaded gasket from holding for any duration.
The fix, is a new bushing and a new water neck fitting.
This is also not an easy bushing to replace, as it involves drive dis assembly.
Next will be the S hose and it's connection to the water neck and the chrome water tube.
Next will be the main suction hose and it's connecting points at the interior side.
Your sea water pump is engine mounted. Anything upstream of this, is on the suction side of the system.
A tiny air breach will absolutely kill suction.
The sea water pump will offer two thrust surfaces for the impeller.... one deep within the body, and the other will the cover surface.
These surfaces must be free from gouges or groves.
The impeller must be resilient, in that the vanes still have elasticity to them as to flex correctly and create the pumping action.
Impellers that remain in the pump body during winter, do not fair well.
You'll know by inspecting it if this should be replaced or not.
From the sea water pump to the Heat Exchanger, is on the pressure side of the system.
If you have a breach here, it will show itself in the form of a visible water leak.
On the pressure side, you'll see a visible water leak.
A breach on the suction side is more tricky to find.
Some will use shaving cream. The suction breach will pull the shaving in and it will disappear at the breached area.
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