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21 Daytona
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Discussion Starter #1
Getting ready to order a mercury kill switch and noticed two different
styles,

Just curious if I ever wanted to run my tank down the track, what is the kill switch required to do?
I can install one that grounds the MSD and shuts down the ignition
or does it need to kill all power?
 

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Getting ready to order a mercury kill switch and noticed two different
styles,

Just curious if I ever wanted to run my tank down the track, what is the kill switch required to do?
I can install one that grounds the MSD and shuts down the ignition
or does it need to kill all power?
On an MSD you want to ground out the box, if using a mag pickup distributor ground the unused white trigger wire to kill. When using a points style distributor or one which requires the white wire to trigger the box, you ground the purple wire on the unused mag pickup lead to kill.

MSD does not recomend cutting power to the box as a saftey/kill feature.
 

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Do you run a MAG or MSD/regular distributer? I don't know how to wire a MAG version, but with the regular distributor/MSD version, you wire the switch into the ignition circuit from the key to the MSD box. The switch is normally closed so the signal from the key switch activates the MSD box. When you pull the lanyard, this disconnects the MSD box from the ignition switch, and shuts the motor down.

If you also use an electric fuel pump, and the pump is turned on via the ignition switch, the pump will also stop when you pull the lanyard. (Assuming that the ignition signal is connected to your pump/relay at the back of the boat, after where you wire the kill switch into the ignition circuit.)

So it should be :
Ignition switch, Kill switch, MSD box and/or electric fuel pump, all in series.
 

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21 Daytona
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Discussion Starter #4
I'm running a MSD 6A and using the white wire to trigger from a Haltech
EMS,
the fuel pumps are controlled by the EMS, they will shut down without a trigger signal.
all I have to do is ground the violet wire to disable the MSD. But wondering if the rules at a track required anything more.
 

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On an MSD you want to ground out the box, if using a mag pickup distributor ground the unused white trigger wire to kill. When using a points style distributor or one which requires the white wire to trigger the box, you ground the purple wire on the unused mag pickup lead to kill.

MSD does not recomend cutting power to the box as a saftey/kill feature.
:))eek:)) are you talking magneto???

the msd boxes i've had all have main +/- power directly connected to the battery. they also have a red ignition wire to the ignition switch to turn the thing on and off. you can wire your kill switch into the ignition wire, OR the primary power wire to the dash, which should shutdown everything operated from the dash. neither of these wires should be the main battery power supply to your msd box.
the purpose of the switch is to shutdown the engine in case you get tossed, not necessarily kill all power to the boat. it's a good idea to have one, even for mild lake/river boats - ask oldsquirt...
in this type of kill switch, the contact "opens" to shutdown the engine. with a magneto, the contact "closes", which grounds the mag shutting down the engine.
 

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:))eek:)) are you talking magneto???

the msd boxes i've had all have main +/- power directly connected to the battery. they also have a red ignition wire to the ignition switch to turn the thing on and off. you can wire your kill switch into the ignition wire, OR the primary power wire to the dash, which should shutdown everything operated from the dash. neither of these wires should be the main battery power supply to your msd box.
the purpose of the switch is to shutdown the engine in case you get tossed, not necessarily kill all power to the boat. it's a good idea to have one, even for mild lake/river boats - ask oldsquirt...
in this type of kill switch, the contact "opens" to shutdown the engine. with a magneto, the contact "closes", which grounds the mag shutting down the engine.
Perhaps my abbreviation was a poor one, Mag Pickup = Magnetic Pickup I guess i figured most ppl would realize that. My bad
 

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Perhaps my abbreviation was a poor one, Mag Pickup = Magnetic Pickup I guess i figured most ppl would realize that. My bad
i see what you are describing josh, under "theft deterrent". i just don't see anything describing that switch being used to shutdown the box.
i still prefer to interupt the 12v ignition source to the box... same wire used to power up/down the msd box everytime the ignition switch is operated. placing the kill switch in that circuit won't do anything more or less than the ignition switch routinely does.

not that i know or not, but it -seems- to me, that leaving the box powered up while grounded through the magnetic pickup wouldn't be a great thing for the box either... dunno, just makes me shudder a little bit.
 

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21 Daytona
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Discussion Starter #10 (Edited)
i see what you are describing josh, under "theft deterrent". i just don't see anything describing that switch being used to shutdown the box.
i still prefer to interupt the 12v ignition source to the box... same wire used to power up/down the msd box everytime the ignition switch is operated. placing the kill switch in that circuit won't do anything more or less than the ignition switch routinely does.

not that i know or not, but it -seems- to me, that leaving the box powered up while grounded through the magnetic pickup wouldn't be a great thing for the box either... dunno, just makes me shudder a little bit.
I see what your saying BP, I posted the question on their site

Wow got a answer already,

"Using the theft deterrent as an emergency kill is an approved method on the 6A product lines.
do not use this option on the digital series boxes"
 

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:))eek:)) are you talking magneto???

the msd boxes i've had all have main +/- power directly connected to the battery. they also have a red ignition wire to the ignition switch to turn the thing on and off. you can wire your kill switch into the ignition wire, OR the primary power wire to the dash, which should shutdown everything operated from the dash. neither of these wires should be the main battery power supply to your msd box.
the purpose of the switch is to shutdown the engine in case you get tossed, not necessarily kill all power to the boat. it's a good idea to have one, even for mild lake/river boats - ask oldsquirt...
in this type of kill switch, the contact "opens" to shutdown the engine. with a magneto, the contact "closes", which grounds the mag shutting down the engine.
now Bob, thats not nice to remind oldsquirt about his swimming days:)hand
 

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ii still prefer to interupt the 12v ignition source to the box... same wire used to power up/down the msd box everytime the ignition switch is operated. placing the kill switch in that circuit won't do anything more or less than the ignition switch routinely does. .

I use this method as it was advised to me by members of this board. Works great to shut her down or keep it from starting when im not in it.. I dont do any racing so i dont know if it is approved for racing but it seems to work great. For me at least.
 
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