What happens when you stop to quick!

Solent Ranger · 28 July 2013, 11:41

The following pictures were taken of a 225 hp outboard which was stopped to quickly. The water went up the exhaust into the engine! Not good

I'm glad it's not mine.

kerny · 28 July 2013, 11:53

wow I thought that outboard engines would have been designed for things like stopping quick.

Hope his insurance pays out.

The Grocer · 28 July 2013, 11:54

Up the exhaust? Really? I would have thought through the air intake more likely - but still difficult!

thomas · 28 July 2013, 12:01

I expect he meant air intake, same thing happened to a friends BMW when he tried to drive it through a flooded road.

Pikey Dave · 28 July 2013, 12:08

Quote:

Originally Posted by thomas

I expect he meant air intake, same thing happened to a friends BMW when he tried to drive it through a flooded road.

Can't see how it could be the air intake, the boat would've sunk first.

Hightower · 28 July 2013, 12:15

Fascinated to hear the story of how it happened?

Nos4r2 · 28 July 2013, 12:30

That looks like it hydraulic locked at speed.

spartacus · 28 July 2013, 12:32

Take it the engine is 'stripped for parts'. Can imagine labour and new parts to rebuild would be prohibitive.

tonto · 28 July 2013, 12:38

Quote:

Originally Posted by Nos4r2

That looks like it hydraulic locked at speed.

+1

Would be interesting to see exactly how that could have happened if the engine was running to get water back past the exhaust valves etc, against the flow of the exhaust gasses?

Festinghouse · 28 July 2013, 14:03

yeah sounds bollox to me, id say def air intake

Leapy · 28 July 2013, 16:27

Quote:

Originally Posted by Solent Ranger

The following pictures were taken of a 225 hp ...

Two possible scenarios? Water into engine somehow and engine threw a rod, or engine threw a rod, punched a hole in the crankcase and water got in?

matt h · 28 July 2013, 16:31

agree, with that, unless the engine had stopped at speed and the water was forced up the exhaust is possible with nil back pressure to hold it back

lightning · 28 July 2013, 17:07

Quote:

Originally Posted by kerny

wow I thought that outboard engines would have been designed for things like stopping quick.

Hope his insurance pays out.

I'd have thought the same.....bad design if that can happen just by stopping quickly.

Dhf · 28 July 2013, 17:14

I'd like to know could this sort of thing happen when launched quickly of the rollers?

Solent Ranger · 28 July 2013, 17:31

Quote:

Originally Posted by matt h

agree, with that, unless the engine had stopped at speed and the water was forced up the exhaust is possible with nil back pressure to hold it back

That is what happened. Or so I am lead to believe. As the engineer working on it said - we will never really know the truth! It happened a week ago!

Peter_C · 28 July 2013, 18:38

Quote:

Originally Posted by tonto

+1

Would be interesting to see exactly how that could have happened if the engine was running to get water back past the exhaust valves etc, against the flow of the exhaust gasses?

Fully plausible, as I have seen it on a V8 powered direct drive inboard boat. The exhaust flapper was defective...errr missing, and it back flowed into the engine immediately seizing it. The event happened as they came to a stop from speed. Required a complete motor overhaul, as it was salt water.

Although on an outboard I am not so sure I understand how? Plus that looks like it locked up at around 2,000+ RPM. Breaking hardened steel connecting rods usually takes more than a failure at idle. Laughingly I have seen many offroad vehicles suck water in and shut down to be cleared out, started back up, and continue down the trial.

Nos4r2 · 28 July 2013, 18:40

Quote:

Originally Posted by Solent Ranger

That is what happened. Or so I am lead to believe. As the engineer working on it said - we will never really know the truth! It happened a week ago!

I reckon someone's telling porkies. It wouldn't have broken the conrod and smashed the crankcase on an attempted restart-thats had water into the cylinders while it's revving.

C2 RIBS · 28 July 2013, 18:49

Quote:

Originally Posted by Nos4r2

-thats had water into the cylinders while it's revving.

How does that occur? stopping fast and reverse and take water into ?

Mollers · 28 July 2013, 18:50

A tripped race boat could give that sort of result. It needs to take a lungfull with revs on to bust things up to that extent. The exhaust/back wash story is guff.

tonto · 28 July 2013, 19:10

Quote:

Originally Posted by Nos4r2

I reckon someone's telling porkies. It wouldn't have broken the conrod and smashed the crankcase on an attempted restart-thats had water into the cylinders while it's revving.

+1

And if it was revving, there is almost no way you can get water back against the exhaust flow, up the exhaust, by the wash following the boat

Thats more like a capsize with the engine revving, and dragging in water through the airbox.