Emergency cut off switch installation

[john from md]

After watching a couple of safety films, I have decided to add a safety cut off switch to my Bayliner. Since I don't have much dash space left, I am planning to use the Sierra switch.

Now to hook it up. I know that the white wire is the shutoff circuit but I don't know if it grounds the CDI's or opens the circuit. The boat is still under its cover so I really don't want to start ohming out wires in the rain.

Can anyone help out here? My plan is to install the switch between the cdi coils and the switch if that will work.

Thanks in advance,

John

 

[Frank Acampora]

Re: Emergency cut off switch installation

The switch should be a normally open one. Parallel the white wire to one lead of the switch and ground the other lead. You MUST parallel so that the ignition switch will still have shut-off function. When the emergency switch closes, it grounds the white wires and CD boxes, preventing spark.

I don't know for sure what exactly is grounded, but if I were designing the CD box, I would ground the switching transistor that dumps the capacitors into the coils. That would be much lower voltage than the 260 that the capacitors contain.

 

[john from md]

Re: Emergency cut off switch installation

Thanks Frank, that's what I was thinking the circuit would look like. Now to buy a switch and get to work.

BTW,

I finished my noise reduction package but won't get to try it until the weather warms up. I consulted with an acoutic specialist and a radar engineer and came up with a cheaper insulation than I was going to buy.

The stuff I bought is sold at Sam's club (util-a-mat) and is a closed cell foam used for putting on the floor for working out or standing for long periods. They sell about 33 square feet or so for $20. It is made to spec ASTM 963-96a.

I have tested it and it appears fuel resistant and weldwood contact cement works on it and the cowl. My test piece had to be scraped off with a razor blade the bond was so good.

My engineer father in law and other friend told me the waffle pattern will scramble the sound inside the cowl and it should easily drop the noise 15 to 20 db.

Now that you know you can get the materials cheap, you need to get a round tuit so you can quiet your engine down too.

Regards,

John