I'm not a natural with electrics, but thought I had a basic understanding of how a coil ignition system works: the battery supplies current, via the ignition switch, to the low voltage circuit which goes through the coil and on to the contact breaker points and then on (via the condenser) to earth. When that circuit is broken (by the points opening) a high voltage current flows in the secondary circuit from the coil to the spark plug.
If that's all correct, then I wonder why, on my wiring diagram (see attached), there are two wires between the ignition switch and the coil. I thought there would only be one.
This is obviously extremely basic, but would someone be kind enough to explain please?
Phil
Under normal conditions, the white wire provides 12 V to the coil causing current to flow through the primary winding to ground. When the points open to interrupt the primary current, this create a large EMF across the primary coil and the secondary coil then effectively acts as a transformation to create a HT voltage across the spark plug.
The other black/white connection to the coil is for use in the ignition switch emergency starting position and effectively switches part of the output from the alternator into the coil to allow starting when the battery is flat. Effectively, this provide an emergency magneto type operation for the bike. One of the problems in this emergency mode of operation is that as the battery starts to charge, the increasing battery voltage opposes that from the alternator until you reach a point that the magneto mode starts to become ineffective and you need to switch from emergency to normal ignition before the bike starts to misfire.
:) :) :) :)
What are items 14 and 19 in your wiring diagram.
Mike 8) 8) 8)
switch position connections.
this is why Im making my own loom as not using that type of switch, I wouldnt use that diagram or components
:) :) :)
Got it Thanks
Mike 8) 8) 8)
The reason I was looking at the wiring diagram is because I've decided to fit an oil tap with a cut-out switch onto my oil feed line in order to prevent wet-sumping. I had a lengthy discussion on this forum a while ago about wet-sumping, and eventually decided to get a BriTie valve, as recommended by people on here whose advice I value very highly. I even went as far as to buy one. But I still had a slight nagging doubt about it, so haven't fitted it. Who knows, I might use it at some stage in the future, but for now I've decided after all to go with a cut-out tap. That's why I was looking at the wiring diagram, to see how to fit it (when it arrives.) Instructions for wiring up the tap are attached below. Looks like I need to split my white (W) wire (see wiring diag) to insert the tap?
Phil
I haven't looked up this device but assume the valve is opened by the switched power supply to the coil. If so, you definitely don't want to use it with the emergency ignition setting otherwise the engine could start with the valve closed :o
As I understand it the normal ignition circuit is made complete when the oil tap is turned on, so you can't start the bike using the normal ignition circuit with the oil turned off.
But actually, I guess if you turned the ignition key to the emergency setting, then you could indeed start the engine with the oil supply off. Hadn't thought of that.
Nothing is simple.
Phil
Just looked it up and can see it's a combined electrical switch and oil tap. I suppose that as long as you turn the tap on before using the emergency setting you would be ok. Quite a neat device and reasonably fool proof :)
seems like a reasonable idea but having worked on customers bikes for a few years, one problem Ive found is with the Yamaha XV535. It has an electrical fuel tap, Ive had a couple that have seized with the weather and dirt. leaving no access to the reserve capacity or if left on the bike runs out of fuel. also the switch to operate is on the handlebars and out in the weather and vibration.
On first reading, I thought this was an electrically operated oil tap but its purely mechanical and the electrical bit is just a linked switch to turn on and off the electrical supply to the ignition coil to stop the engine firing up without the oil supply turned on.