Hard (re)starting list-side engine (ballasted AR240, wake surfing)

[swatski]

the water pick up line is in the jet nozzle at idle this is below the water line but load up ballast and it gets pushed very deep under water especially when the boat comes to a stop when the wave washes up on the back deck add in the extra pressure of water. This water gets forced into the exhaust on the opposite side of the water lock

I think @Cambo 's theory is a good theory. Well-reasoned and well-thought out.

I don't even know Why I'm responding, this starts feeling like beating a dead horse, sorry!

The intakes do not lead to cylinders (directly), the only way for water to get there is to completely fill the exhaust first... That will simply not happen with the engines ON.

So- assuming the engines are ON while surfing (sic) the wave washing up and swamping the back deck, could be a tsunami - I don't care, it is not moving up the exhaust, or accumulating in the exhaust, with the engines ON...

You really have to work on it to get the water past the waterlocks/boxes in those engines - it takes moving at speed with the buckets down, wherein water is pushed up the intakes (under the boat) with the buckets down water can enter (through the pump intakes) all the way into the exhaust and fill those up - due to pressure building in the pumps (when for example towing at speed with the buckets closed/down).

The above scenario can only happen WHEN THE ENGINE(S) IS OFF and the boat is moving fast, with the buckets down.
Alternatively, it can also happen on the hose with high water pressure - when water pressurizes the system as the flushing ports are above the seats in the gunnels.
Again, ONLY when the engines are off and the boat is moving or being flushed on a hose (water entering at high pressure through ports located above the deck/seats).

Sitting in the water with engines off will NOT lead to hydrolock under any but the most extreme submerging conditions, or engine bay swamping (albeit that would let water in through air intakes not exhaust, so that's different).

--

 

[Shady28]

This thread saved a day of surfing or at least a bit of my time and sanity.

Full ballasts, killed the engines to relax for a bit and when we went to surf the listed side engine wouldn’t start. After 3 tries I remembered this thread vaguely, had everyone (9 people) step over to the non-listed side and it fired right up!

Another proof point for the exhaust and water pressure theory. Thanks guys!

 

[Hickmaster2001]

Has there been any other solutions to this issue? Or is everyone agreed on the heat soak and blower as the solution? please let me know if that’s still the case or of anything new as I will sell this boat if it keeps happening. Thanks! Mike

 

[Cobra Jet Steering LLC]

I believe if you start the higher engine and get the boat moving forward or to the side away from the low side and then try to start the engine it usually starts , the issue is INCREASED BACK Pressure on the low side exhaust

 

[Hickmaster2001]

I believe if you start the higher engine and get the boat moving forward or to the side away from the low side and then try to start the engine it usually starts , the issue is INCREASED BACK Pressure on the low side exhaust

Thanks for the reply and agree on additional back pressure contributing. Just wonder if anyone ever came to the “aha” moment with a specific issue and solution other than what been discussed/tried on the previous posts in the thread since it’s been some time now. Thanks! Mike

 

[Cobra Jet Steering LLC]

What I recall is once people did the low engine with the boat moving it solved the issue.