Ropes around the propeller winding the engine round (with the "stop" button on)

[Cadence]

Originally Posted by boatman61

They (decomp levers)come in very handy when the engine won't stop..
As for diving on it.. all well and good if the sea's calm.. but you can have all the dive gear you want in a seaway and you still stand a good chance of having the hull crush your head or the prop split your skull..

A piece of rain gear over the air intake works also. Not being funny. The post was a proper marine diesel has a compression release? I agree getting beat over the head by the hull probably is not a good idea.

[Sailorbob8599]

Originally Posted by boeing1

never tried it myself but I know people that have tried it and claims it works, I would think it would depend on how fast the engine was running when you raped the rope around the prop

??????????????Howja do that?????????????

[Capt Gill]

Originally Posted by Wotname

The stop button should be on so fuel is not being feed into the cylinders and pooling there and then unburnt fuel is forced into the exhaust system.

It is not to prevent the engine from starting, the decompression has already taken care of that.

Of course this will go over the heads of those who don't have an engine decompression device .

For those who don't have a compression release, e.g., the ubiquitous Perkins 4-108, the decompression effect can be achieved by sealing off the air intake with a large bung or the like (insure that it won't be sucked into the combustion chamber). The kill switch/cable still needs to be engaged for the reasons mentioned.

[charliehows]

Originally Posted by boatman61

They (decomp levers)come in very handy when the engine won't stop..
As for diving on it.. all well and good if the sea's calm.. but you can have all the dive gear you want in a seaway and you still stand a good chance of having the hull crush your head or the prop split your skull..

not to mention bleeding the fuel system, setting the tappets, testing the water and fuel pumps, occasionally bumping the flywheel forward if it stops at one of those spots that bounce the starter cog, hand starting by decomping one cyl. , probably afew other useful things i've forgotten to mention...

[Capt Gill]

Originally Posted by charliehows

not to mention bleeding the fuel system, setting the tappets, testing the water and fuel pumps, occasionally bumping the flywheel forward if it stops at one of those spots that bounce the starter cog, hand starting by decomping one cyl. , probably afew other useful things i've forgotten to mention...

Not quite as convenient as a compression release, but all the above can be accomplished by blocking off the air intake.

[Wotname]

Originally Posted by Capt Gill

Not quite as convenient as a compression release, but all the above can be accomplished by blocking off the air intake.

I don't undertand, how does blocking off the air intake assist in turning the engine over for the reasons charliehows mentioned.

[Cadence]

Originally Posted by Wotname

I don't undertand, how does blocking off the air intake assist in turning the engine over for the reasons charliehows mentioned.

I've used blocking off air to stop a shot diesel running on sump oil. I'm wondering if using it to prohibit starting might not load the cylinders up with fuel? It might be a small aggravation if it clears the wheel of line. I don't believe I'd do it for long.

[Capt Gill]

Originally Posted by Wotname

I don't undertand, how does blocking off the air intake assist in turning the engine over for the reasons charliehows mentioned.

In blocking the air intake there is no or v.little air to compress therefore the engine will spin quite freely.
Cadence wrote:
"I've used blocking off air to stop a shot diesel running on sump oil. I'm wondering if using it to prohibit starting might not load the cylinders up with fuel? It might be a small aggravation if it clears the wheel of line. I don't believe I'd do it for long."
Engaging the kill switch/cable prevents fuel from the HP pump to the injectors, therefore no fuel in the combustion chamber(s).

[Wotname]

Originally Posted by Cadence

I've used blocking off air to stop a shot diesel running on sump oil. I'm wondering if using it to prohibit starting might not load the cylinders up with fuel? It might be a small aggravation if it clears the wheel of line. I don't believe I'd do it for long.

I agree, I think it would load the cylinders with fuel which I believe is why Tom Cunliffe advises to operate the engine stop button / lever as well (see the OP).

[Wotname]

Originally Posted by Capt Gill

In blocking the air intake there is no or v.little air to compress therefore the engine will spin quite freely.
.......

Hmm... While I haven't tried this, I would have thought the vacuum created would be almost be as much of an hindrance as the compression is and prevent the engine from spinning freely. I must try it the next chance I get.

[Jim Cate]

Originally Posted by Wotname

Hmm... While I haven't tried this, I would have thought the vacuum created would be almost be as much of an hindrance as the compression is and prevent the engine from spinning freely. I must try it the next chance I get.

Dunno how one gets a good enough seal to keep air out of the intake manifold, so I must agree that this seems sketchy. Do let us know how it works, Wottie, and how you keep the air from leaking in.

Jim

[IdoraKeeper]

Oh the humanity! what would cruising season be without a dingy painter in the prop?

[Capt Gill]

Originally Posted by Jim Cate

Dunno how one gets a good enough seal to keep air out of the intake manifold, so I must agree that this seems sketchy. Do let us know how it works, Wottie, and how you keep the air from leaking in.

Jim

I've done this a number of times on my Perkins 4-108, mostly for bleeding the high press. part of the FI system, initially just using the palm of my hand which would suck the blood to the surface sorta like getting a hickie, now I use a large bung with a bit of teflon tape wrapped around it where it meets the air horn. Of course, if bleeding the system you'll want the throttle full on and the kill switch/cable disengaged; for other work kill sw./cable engaged and throttle at idle to prevent raw fuel from accumulating in the combustion chamber.

[Cadence]

Originally Posted by IdoraKeeper

Oh the humanity! what would cruising season be without a dingy painter in the prop?

That or a warp. in Maine or the Keys.

[SeaLoon]

Dear Metallon,

First, you need to remember when Tom C. was writing this.
1. Older diesel engines had a decompression lever, no compression, no run.
2. The "stop" button is probably much the same as the "off" switch on a diesel where the fuel solenoid is closed, i.e. no fuel can enter the engine for it to crank.

I remember, quite embarrassingly, when anchoring off an island in Turkey on a charter boat many years ago(with my fiancee), I managed to get a polypropylene stern line wound very tightly around the prop shaft while reversing. After my NUMEROUS attempts, while free-diving, to saw through the line with a dull bread knife, a Brit on an adjacent sailboat rowed over and calmly put my engine in neutral, had me pull firmly on the line, and turned the shaft by hand in the forward direction (remember I had backed over the line) until about 25' of line came free. Then, sweaty from the engine room, with his hands and arms covered in grease (remember, charter boat) he calmly got back in his boat and rowed away. A lesson well learned for me and much appreciation for how sailors will help each other.

Have fun sailing. It's the most fun I've ever had in my life!

And to para-quote, Wind In the Willows: "Believe me, my young friend, there is NOTHING--absolutely nothing--half so much worth doing as simply messing about in boats...."

plus a favorite saying: ~~_/) ~~ There is no such thing as a bad crew.. Only a bad captain.. ~~_/) ~~~~

Regards