SailNet Community

SailNet Community (http://www.sailnet.com/forums/)
-   Gear & Maintenance (http://www.sailnet.com/forums/gear-maintenance/)
-   -   Diesel Shutoff (http://www.sailnet.com/forums/gear-maintenance/102815-diesel-shutoff.html)

davidpm 08-22-2013 12:37 AM

Diesel Shutoff
 
The boat I was on tonight has separate throttle and gearshift on the same axel. The gearshift is longer.

The way you shut off the engine is to pull the throttle all the way to the stern.

The problem is that their doesn't seem to be any way to know exactly where idle is vs off.

Is this normal or is their supposed to be a spring that you have to overcome to shift to off?

mark2gmtrans 08-22-2013 12:44 AM

Re: Diesel Shutoff
 
This is something I have seen on a few boats and a ton of heavy machinery. It should probably have at one time had a spring on the throttle adjustment down on the fuel pump end of things that would help you feel it. It may still be there, but it probably is not all that springy anymore.

Basically all this is doing is starving the engine for fuel by completely shutting off the throttle to a setting where no fuel at all should be going to the engine. The little spring that may possibly have been there at one time a long time ago would just have been to kind of keep the throttle from going there on its own. Since the cables are usually stiff enough, I never worried about it.

Capt Len 08-22-2013 01:10 AM

Re: Diesel Shutoff
 
Potential problem can be a partial shutdown and restart just as engine revs go to zero. .bounces on top dead center ,fires backwards and sucks up exhaust water, bending at least two con rods and costing about 8 grand to make right. Don't ask how I know this. A separate non slip in your hand pull knob isn't foolproof but it helps.Don't let it go until oil alarm rings.

bristol299bob 08-22-2013 10:42 AM

Re: Diesel Shutoff
 
I've got the same setup on my boat. You bring the throttle back until you feel resistance, that's idle. Then there is a spring that lets you push it another 3/8 of an inch to shut her down.

Here's some pics (before I cleaned and painted!). You adjust the idle speed with threaded portion and locknut. There is a spring that you cant quite see in either pic that allows you to push it further and shut it off.

https://lh3.googleusercontent.com/hL...M=w735-h605-no

https://lh3.googleusercontent.com/-J.../throttle1.JPG

kd3pc 08-22-2013 10:51 AM

Re: Diesel Shutoff
 
Quote:

Originally Posted by davidpm (Post 1077624)
The boat I was on tonight has separate throttle and gearshift on the same axel. The gearshift is longer.

The way you shut off the engine is to pull the throttle all the way to the stern.

The problem is that their doesn't seem to be any way to know exactly where idle is vs off.

Is this normal or is their supposed to be a spring that you have to overcome to shift to off?

My 1983 Sabre was that way, and boy was it a surprise when the boat was new and the first time I came in to dock bringing her home, and had both a current and the wind at my back and throttled back in forward, went to reverse and was set to throttle up to settle us along side the dock...when I apparently pulled too hard and she stalled. My wife was rattled and never the same. Saved the boat, as I had snagged the pile and had a spring line on it and she started right back up, but it was a learning experience....reinforces the never approach anything solid that you don't want to hit...you just never know.

MarkSF 08-22-2013 01:45 PM

Re: Diesel Shutoff
 
"reinforces the never approach anything solid that you don't want to hit...you just never know.'

I was approaching a dock in a Catalina 27, put it in reverse, tried to apply some throttle, and the throttle lever came off in my hand. Fortunately, idle in reverse was sufficient to almost stop the boat.

MarkSF 08-22-2013 01:47 PM

Re: Diesel Shutoff
 
Quote:

Originally Posted by mark2gmtrans (Post 1077626)
This is something I have seen on a few boats and a ton of heavy machinery. It should probably have at one time had a spring on the throttle adjustment down on the fuel pump end of things that would help you feel it. It may still be there, but it probably is not all that springy anymore.

Basically all this is doing is starving the engine for fuel by completely shutting off the throttle to a setting where no fuel at all should be going to the engine. The little spring that may possibly have been there at one time a long time ago would just have been to kind of keep the throttle from going there on its own. Since the cables are usually stiff enough, I never worried about it.

What could be happening is that the whole mechanism is stiff enough that you can't feel the idle position, maybe combined with a weak spring. Consider lubricating everything in the throttle mechanism.

davidpm 08-22-2013 02:53 PM

Re: Diesel Shutoff
 
Quote:

Originally Posted by Capt Len (Post 1077636)
Potential problem can be a partial shutdown and restart just as engine revs go to zero. .bounces on top dead center ,fires backwards and sucks up exhaust water, bending at least two con rods and costing about 8 grand to make right. Don't ask how I know this. A separate non slip in your hand pull knob isn't foolproof but it helps.Don't let it go until oil alarm rings.

Can the pull knob be added to the setup and the throttle setup so it can't shut the engine off.?

I'm thinking that this is not engine dependent but depends on how it is setup?

It can be changed to a single lever setup too.
I was at an ASA school and he was converting all his boats to single lever as he got sick of rebuilding transmissions.

captbillc 08-22-2013 03:31 PM

Re: Diesel Shutoff
 
my yanmar 2GM20F has a separate pull knob to shut off the fuel . the engine will not stop without pulling the knob. no problem with this & the morse single lever control that controls the throttle & shift.

mark2gmtrans 08-22-2013 10:52 PM

Re: Diesel Shutoff
 
Quote:

Originally Posted by MarkSF (Post 1077862)
What could be happening is that the whole mechanism is stiff enough that you can't feel the idle position, maybe combined with a weak spring. Consider lubricating everything in the throttle mechanism.

On heavy machinery it is usually the size and age of the cable, they are LOT bigger diameter than the smaller ones on the boats, and they are just really stiff in the sleeve. The ones I have had the same thing happen with on a boat were most likely in need of lube in the cable itself, and the throttle mechanism. The reason I did not mess with it was because being stiff kept it from being an issue about turning itself off unexpectedly LOL. If I had lubed everything up, then I would have had to fix the spring and the little detent, and it was not a boat that was mine, except one time, and that one was getting new everything as soon as it got home.

I would certainly not like the motor to go off without permission, that is not fun.


All times are GMT -4. The time now is 02:47 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012