Re: 86 Evinrude 15 Tiller handle shocked me?
OK, ...If you look at the schematic for the ignition system very closely, you'll notice a couple of conventional terms. Most folks think that ground is zero volts, but in this case, that's not so. They refer to the 'ground' symbol , not so much as electrical ground ,but as a 'point of connection'. The powerhead, mounting bracket, lower unit etc. are all at 180VDC voltage potential because they are connected. The metal boat that the motor is mounted to is also at this voltage. You might ask, "Why don't I get a shock"?? You don't get shocked because there is no exposed electrical path back to true electrical 'ground'. This 'electrical ground' is inside of the sealed powerpack and is the negative side of the charge capacitor. There is only one path to this 'ground' outside of the powerpack, and that's the 'kill' wire'. <br /><br />You can test this using a volt meter. <br /><br />TEST #1:<br />Put the BLACK lead on the powerhead (which most people think of as ground) and the RED lead to the kill wire that goes TO the powerpack. Start the motor, you'll read MINUS (-)180 volts.<br /><br />TEST #2:<br />Reverse the test leads, place the RED test probe anywhere on the powerhead, connect the BLACK test probe to the kill wire that goes TO the powerpack. Start the motor, you should read PLUS(+)180 Volts of the powerpacks charge capacitor. <br /><br />This clearly shows that the powerhead is PLUS voltage and the kill wire as NEGATIVE, and is the reverse of what most people think.<br /><br />Test #2 above can be performed on a running motor to test that the charge coil under the flywheel is working and that the powerpacks full wave bridge and charge capacitor are OK, at least with this motor and model powerpack.<br /><br />What OMC is doing is using the powerhead as a conductor. The small black wire coming out of the powerpack that has a spade lug is connected to a powerpack mounting bolt. This wire is the 180 volt output of the charge capacitor. That's why it's important to have the small wire of the externally mounted coils securely mounted under a coil mounting bolt, this is where the coils are getting their primary coil voltage from, from across the powerhead itself.<br /><br />You then might ask, 'How is it possible for the coils HIGH voltage (spark plug wire) to jump the plug gap to a ground that you claim isn't really a ground at all"??<br /><br />It's simple, and I'll use an analogy.<br /><br />Say you were a passenger in a small plane wearing a parachute. You are flying at 30,000 feet and you jump out of the plane. You are supposed to pull your chute before you get to the ground, right?? RIGHT!!<br />But what if , before you pull your chute you hit the top of a building that's 180 feet high. You're as dead as Julius Caesar. For all intents and purposes, you hit 'ground'. In this analogy, you are the high voltage, starting out at 30,000 volts and trying to reach the 'ground'.<br /><br />This is the same reason why the high voltage secondary (30,000 volts) can jump to the 180 volt powerhead, it's not zero voltage, but it's close enough to a ground potential that the spark jumps.<br /><br />I can assure you that the charge capacitor does have enough capacity to knock you're socks off if you touch the powerhead, mounting bracket, or metal boat AND touch the kill wire. The stored voltage capacity of the capacitor will discharge through you. <br /><br />Now unless they changed the wiring and functional theory as outlined in my manual for my '79 15hp or my '86 6hp, yours should be about the same. <br /><br />I'll take a guess that when you grabbed the tiller handle, you didn't grab the rubber twist part of the grip. You're fingers grabbed the underside opening on the tiller handle (where the 2 kill wires are). There was a bare wire (the one going to the powerpack), and your hand was wet. Your fingers and hand bridged the bare wire and the metal tiller handle. You then became part of the 'kill circuit' and got shocked. <br />As long as the flywheel is spinning, the charge coil under the flywheel is charging the ignition capacitor. Since your hand and fingers are not a perfect conductor, it probably didn't kill the motor, but I'll bet the motor stumbled a bit, when YOU got bit.
