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06-09-2006, 14:49
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#1
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Guest
Posts: n/a
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Why rig starters this way?
To engage the starter on the diesel in my sailboat you have to turn the key AND push a button at the same time. I had thought this was one of those peculiar quirks of an old, much modified, boat but have seen the same arrangment on several other sailboats.
My question is: Why?
I know that MOST boats do not have such an arrangement, but it seems common enough that some people must think it is a good idea.
I only ask because I am rebuilding the engine panel and want someone to convince me I should keep the push button that is in series with the starter switch in the key.
Bill
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06-09-2006, 14:53
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#2
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֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,136
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Bill, it sounds like someone couldn't find a proper ignition switch assembly and so just stuck in a starter switch and a key lock switch.
Whatever works for you.
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06-09-2006, 16:18
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#3
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Senior Cruiser
Join Date: Feb 2003
Location: Macatawa Michigan
Boat: Amanda Faye 61' Custom Irwin aftcockpit ketch
Posts: 1,415
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I installed my new Westerbeke in 2002 and it is the same way. In my case it is to preheat the air intake.
__________________
Gunner
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06-09-2006, 16:21
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#4
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Registered User
Join Date: Jun 2005
Posts: 1,901
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Bill,
I assume you have a Westerbeke or Universal. The reason is to confirm activation of the pre-heat system.
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07-09-2006, 03:51
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#5
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Registered User
Join Date: May 2003
Location: New Bern, NC
Boat: Prout Manta 38' Catamaran - Sunspot Baby
Posts: 1,521
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I have buttons becuase when my switch started to fail, I was in Bahamas and didn't want to fly in an expensive Vovlo switch. I bought a button on Staniel Cay and installed it.
When the other switch started acting up going north, I matched the set up on the other engine.
It is probably a previous owner of your boat took a similar tack.
George
__________________
She took my address and my name
Put my credit to shame
Sunspot Baby, sure had a real good time
Bob Seger
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07-09-2006, 06:15
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#6
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Registered User
Join Date: Aug 2005
Location: NSW Central Coast
Boat: Lagoon 410 (now sold)
Posts: 514
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My Bukh DV20 works the same way, and the owners manual says to push it in when starting, and push it in when turning off.
If I don't push in when starting, the motor cranks but does not start. So I think the non depressed position must activate the fuel cut-off solenoid for some reason. Similarly if I just switch to the off position it does not stop, so must NOT be activating the fuel cut-off solenoid.
What I don't understand is why the start key must be released the instant the engine fires. If I don't, the alarm will sound.
I actually burnt out the fuel cut-off solenoid by misuse of the start key. My daughter started the engine and must not have released the key in time. Sadly, the alarm was inoperative at the time, so we were unaware of the problem until about 10 minutes later when the solenoid started smoking. By then it was too late, so I had to use the decompression lever to shut it down.
The Bukh representive said this was a common occurrence, and was caused by putting the key in wrong position. The owner's manual warns about leaving the key in the wrong position due to high current usage by the solenoid.
Still doesn't make sense to me why it would burn out when the engine is running.
__________________
Steve
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07-09-2006, 09:01
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#7
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֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,136
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"The Bukh representive said this was a common occurrence," Engine controls that make minor fires a common occurence...hmmmm.....One can only wonder what the schematic for that system looks like, and what makes them think it is a better idea to do things that way.
One ignition key (spring loaded) and one manual "preheat" button, also spring loaded, if there are glow plugs or something else that might need to be used "but not all the time"....would seem to be the simplest way to do it, given that most boaters have been trained on auto ignition keys.
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08-09-2006, 08:33
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#8
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Guest
Posts: n/a
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Thanks for the thoughts... but no good answers yet....
Partly because I was not clear enough in my original description. The engine is a Westerbeke 4-154, vintage 1974. It is NOT the preheat... that is a seperate button not at all interlocked to the starter. The panel has the keyswitch and three buttons. Preheat, Start (the topic of this thread) and stop (which activates a solenoid to shut off fuel at the injection pump).
The key switch is a standard 3 position switch (off-run-start) switch. To run the starter you must push turn the key to start, and push the button. The button is simply in series with the key switch in the power to the starter solenoid.
A bit of research in the service manual confirms that this was the original factory design, but still no clue as to why....
As an aside, I have yet to go sailing in weather where the pre-heat had any effect on the engine start at all. Down to 40F it just fires right up, pre-heat or not. None too shabby for a 30 year old engine with 6200 hours.
My theory? In a salt water world, the spring return on the start key switch is less than 100% reliable, so the momentary contact push button protects the starter from a sticking key switch. Lame, I know, but it is best I can come up with!
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08-09-2006, 10:14
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#9
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,143
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"... The button is simply in series with the key switch in the power to the starter solenoid ...
... the momentary contact push button protects the starter from a sticking key switch ..."
A series Pushbutton serves no practical purpose in the situation you describe. Granted, it is cheaper to build a more robust Momentary Push Button Switch (than a robust Ignition Sw), but the cost of a cheap Ignition Switch plus a P.B. would exceed the cost of a robust ignition switch. Accordingly, I am suspicious of the claim that it's factory wiring, and of no additional purpose (such as pre-heat).
I once installed a parallel P.B. (directly to starter) in an old 457 CID Chevy truck, because the solenoid would sometimes "stick" due to high temperatures and poor heat shielding.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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08-09-2006, 10:54
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#10
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Guest
Posts: n/a
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Quote:
Originally Posted by GordMay
Accordingly, I am suspicious of the claim that it's factory wiring, and of no additional purpose (such as pre-heat).
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It's not exactly a "claim"... it's the way the service manual draws the wiring diagram... the preheat pushbutton really is a seperate circuit.
Quote:
Originally Posted by GordMay
A series Pushbutton serves no practical purpose...
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I SAID my explaination was lame! and so far nobody has a better one!
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08-09-2006, 11:00
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#11
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֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,136
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Ummm...maybe the "twist and push" design is supposed to be a safety, to prevent rugrats from accidentally starting the engine? I've seen stranger "safety interlocks" used. In fact, there's an identical one in the sunroof of my car, you have to push a button AND hold in the motor switch to close the hatch. (Well, somehow that safety button jammed in the "on" position in the first week I owned it.<G>)
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09-09-2006, 05:28
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#12
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Senior Cruiser
Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,143
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Not to put too fine a point on it, and certainly not intended as a criticism:
"... the way the service manual draws the wiring diagram... the preheat pushbutton really is a seperate circuit ..."
A component (ie: P.B.) is usually considered to be part of a single circuit, when it is wired in series, and either enables (normally open) or disables (normally closed) other components in the same circuit.
I would usually reserve the term "separate circuit" for those elements that are wired in parallel.
Your supposition is not as "lame" as is the redundant series P.B. ~ could just be a quirky "Lucas" peculiarity.
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"
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09-09-2006, 07:55
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#13
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֍֎֍֎֍֎֍֎֍֎
Join Date: Apr 2006
Posts: 15,136
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"could just be a quirky "Lucas" peculiarity."
Lucas, as in that revered British institution lovingly referred to by sports car owners as "The Prince of Darkness" ? <G>
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