Test starting a renovated engine

[Swanrad2]

Hi, I am doing a first start on our MD11C this weekend having done a lot of work. I suspect the engine stop won't work (or at least have to proceed as though it won't due to earlier issues - but I won't know until after it has started) so I need a plan B to stop the thing. I checked out the space between my head and the flywheel at the weekend with a view to using the 'cracking off the injectors' method - and it was a little tight for me. This is, therefore, now plan C.

So plan B is a plank with two caps screwed to it that will be placed over the air filter housings to starve the engine of air if it won't stop. The caps are a decently tight fit, I can squeeze in a bead of silicone and let it set if needed and be pretty confident it won't get sucked into the engine...

Anything else need doing to perfect plan B, with a view to avoiding Pan C. Or is I all a terrible idea and here is plan D?

 

[robmcg]

Tea towel over the air intake will stop it in a few seconds. Make sure it doesn't get wrapped up in the alternator belt or fly wheel.

 

[lw395]

Is there no decompressor?
Will the vacuum destroy the air filter housing?

 

[NormanS]

Presumably you have some way of shutting off the fuel.

 

[lw395]

Mate of mine stripped and rebuilt an old generator.
Unfortunately some part of the governor or injector pump went together wrong and it eventually started but tried to rev like a grand prix Suzuki.
Luckily we stopped it on the decompressor before any damage was done.
I suspect the engine may run for a while with the fuel tap off, and there is sometimes the possibility of it running on its lube oil if there is an issue with rings or guides.
If any air can get into the fuel system under vacuum, it will use all the fuel down stream of the air leak before stopping.
Being ready to either decompress or stop the inlet would be good IMHO.

 

[sailorman]

Tea towel over the air intake will stop it in a few seconds. Make sure it doesn't get wrapped up in the alternator belt or fly wheel.

It will certainly stop the engine
WHEN IT GETS SUCKED IN :encouragement: then another re-build

 

[robmcg]

It will certainly stop the engine
WHEN IT GETS SUCKED IN :encouragement: then another re-build

It won't get sucked in, the air intake is not a turbine! Tried and tested from experience!

 

[aquaplane]

If you have the hatch off the cockpit sole you can activate the engine stop manually, I had to do this while I was waiting for a new cable.

If that doesn't work, lift both decompressors.

I doubt the air filters will implode under vac, the maximum possible pressure is only 1 bar. Any old stray plastic bag will stop an engine starting (don't ask me how I know this, I just do OK) but I don't know if it will stop one that is going.

 

[sailorman]

It won't get sucked in, the air intake is not a turbine! Tried and tested from experience!

one went into my old YSE 12 pdq , luckily the inlet valve stopped it :disgust:

 

[robmcg]

one went into my old YSE 12 pdq :disgust:

Oops!

 

[[448]]

Good luck. I've got a md11c bottom end with rods, 1 barrel and 1 piston if it all goes wrong.
Decompressors the best emergency stop. I wouldn't stick anything over the air intake.
Ruairidh

 

[Swanrad2]

Good luck. I've got a md11c bottom end with rods, 1 barrel and 1 piston if it all goes wrong.
Decompressors the best emergency stop. I wouldn't stick anything over the air intake.
Ruairidh

I like to be clear (I need a process because quick thinking, engine and me don't mix)-

1. Turn the engine over with decompressors lifted to get some oil circulating
2. Sit there worrying for a bit
3. Start the thing
4. Assuming the governor is OK and it doesn't eat itself try the engine cut off manually
5. If that doesn't work - lift the decompressors
6. If that doesn't work I'm going to stick with my plank and lids
7. Last resort is to crack the injectors

I have heard of MD11Cs blowing themselves up because of governors sticking so am being super-cautioius.

 

[KellysEye]

> MD11C

We had one of those there are decompression levers on top of the engine, just lift them up.

 

[ganter]

I like to be clear (I need a process because quick thinking, engine and me don't mix)-

1. Turn the engine over with decompressors lifted to get some oil circulating
2. Sit there worrying for a bit
3. Start the thing
4. Assuming the governor is OK and it doesn't eat itself try the engine cut off manually
5. If that doesn't work - lift the decompressors
6. If that doesn't work I'm going to stick with my plank and lids
7. Last resort is to crack the injectors

I have heard of MD11Cs blowing themselves up because of governors sticking so am being super-cautioius.

That sounds like a good process.

One edit though:

1. Turn the engine over for some time with the decompressors lifted to get lots of oil circulating.

 

[alahol2]

That sounds like a good process.

One edit though:

1. Turn the engine over for some time with the decompressors lifted to get lots of oil circulating.

Unless the boat is in the water in which case this could fill the exhaust pipe with water and backfill into the engine via the exhaust valves and then you will have to rebuild again.

 

[[448]]

Unless the boat is in the water in which case this could fill the exhaust pipe with water and backfill into the engine via the exhaust valves and then you will have to rebuild again.

Not if you've got the inlet water turned off whilst you are churning over!
Ruaridh

 

[LittleSister]

Not if you've got the inlet water turned off whilst you are churning over!
Ruaridh

And better still? - Turning the water inlet off after letting it flow briefly, so that the water pump impellor is not running completely dry.

 

[UncleAlbert]

Good luck. I've got a md11c bottom end with rods, 1 barrel and 1 piston if it all goes wrong.
Decompressors the best emergency stop. I wouldn't stick anything over the air intake.
Ruairidh

And I have another barrel and piston to go with it.

 

[fisherman]

Here's how it's done, and running backwards, to boot:

http://www.youtube.com/watch?v=AG1MnXkHhlM

 

[Lakesailor]

I love that video.