In article , Rick
writes:

Do you know if the fuel solenoid is engergized to run or to stop?

Rick

The solenoid has to be energized to stop the engine.

I may not do anything to my friend's boat but just as an exercise in elementary
circuit logic I'm using Turbocad and trying to design the simplest circuit to
allow an engine to be controlled entirely by the key switch.
My parameters a no modifications to the fuel injector or engine, no solid
state components, IE no 555 chips, nand gates, and gates ETC. I'd like my
device to be just an add on, keeping the kill button active and using the
existing key switch.
My circuit would consist of dpdt relays and time delay relays. Since the boat
may not be used for a month or more at a time, the system cannot have any
devices which would drain the battery during nonuse without any extra switches
to turn off. So far this last requirement has been my biggest hurdle.

I wrote:
A friend just bought a yacht with twin Hino diesels. They are started by a key
switch but when they you want to shut them off you have to press a stop button
until the engines quit, then turn the keys off. I don't have much experience
with diesels but years ago when I had a job repairing forklifts I ran into a
similar situation. This seems to me to be unnecessarily complicated. After all,
most diesel powered cars turn on and off with a key switch. I have asked many
people this question but have gotten answers that didn't seem plausible. So now
I'm asking the experts. Thoughts?

On 25 Sep 2003 06:01:35 GMT, (Engineman1) wrote:
I'm thinking of bypassing the stop button with a normally closed relay which
when the keyswitch is turned on will open and release the solenoid which is
stopping the fuel supply. When the key is turned off the solenoid will be
energised and cut off the fuel. Since we don't want to run the batteries dead
over a long period we'd have a time delay relay to cut off the power to the
solenoid and itself after say, 5 minutes. This I hope is a simple method of
accomplishing this purpose with easily obtained materials and not having to
make major changes to the system, or is there a loophole in ny logic?
Engineman1

Sounds to me like you're just adding complications, ie more things that
can go wrong.

Gary