Cooling water flow & hydro-locking

[TeeNGee]

Does the water highlighted in blue cool the exhaust manifold and enter the head without mixing with exhaust gases?
Is the red highlighted water flow the only water that mixes with the exhaust gases and subsequently cools the remainder of the exhaust (water lock, resonator, exhaust valve, & associated hoses) and out through the exhaust valve?
If this is the case, the water lock would need to fill to the level of the exhaust valves before water could cause a hydro-lock.
Am I interpreting these schematics correctly?

 

[Neutron]

I dont see anything highlighted in the schematic. Water and exhaust gasses only mix at the very end of the manifold near the rubber coupler. Before it enters the water box

 

[anmut]

If this is the case, the water lock would need to fill to the level of the exhaust valves before water could cause a hydro-lock.
Am I interpreting these schematics correctly?

I believe this is correct. Takes a bit of time to fill the exhaust with water before it overflows through the valves and into the cylinders.

 

[TeeNGee]

I dont see anything highlighted in the schematic. Water and exhaust gasses only mix at the very end of the manifold near the rubber coupler. Before it enters the water box

Second page of the attachment has the highlights.

 

[Neutron]

You should post the picture, not an attachment, its not showing up

 

[TeeNGee]

You should post the picture, not an attachment, its not showing up

They are pdf.
Here are screenshots.

 

[Neutron]

That is correct flow

 

[DSG!]

We all know the precautions regarding towing or single engine operation of a Yamaha jet engine.

So what is the recommended procedure should you have an engine quit while at speed - which of course creates a significant backwash? Should the bad engine be secured and assumed to have a hydrolock prior to attempted start?

 

[BumbleBee255]

So, in the first schematic, hose "B" would be the hose to clamp/shut off for towing? Sorry for the question in the middle of your thread.

 

[TeeNGee]

If you can't get to hose "B", based on @Neutron 's reply the only hose that could hydrolock an engine is the hose that dumps water into the exhaust gas flow and into the water lock (highlighted in red in the Cooling Water Flow schematic). The rest of the water goes overboard through "C" & "D".

 

[Neutron]

To test that theory which i believe is correct, you could run on hose, watch water flow out the exhaust then clamp off that line and it should stop flowing out the exhaust