What do I actually need? Electrical wise, tracker build

I have a 1975 XS650 that I am turning into a street tracker type bike and I am getting to the electrical part of the project... I am a mechanical engineer by profession but my electrical knowledge is "lacking" haha. I am wondering what I actually need on the bike, I want it to be as bare bones as possible, but I still want to have a battery. I have already removed the electric starter so it is kick only at this point.

As far as lighting goes...

I have a headlight (I think it has a high beam), taillight and brake light, I do not need to have turn signals, but those are something I can always work in later.

I did build a harness for my 2008 WR250F that had all of the lighting stuff but as far as the electrical that the engine needs to run, I know nothing about.

I plan on using hydraulically activated bajo bolts for my brake light switches. I want this to be as simple as possible from a controls standpoint: When the bike is on I want the headlight and taillight on, I want a separate switch for my high beam (I can mount it onto of the headlight housing) and then my brake light switches at the master cylinders.

As far as the engine electrical goes, I am using a pamco pete electronic ignition (rephased) and the green coils.

I have the 3 wires per side that come off of the electric ignition unit and I know that 2 go to each coil and the 3rd one gets grounded. I know I need some sort of regulator or rectifier or something, and this is where my knowledge drops....

What do I need to make this bike run? If so, what do I need and how do I hook it all up. I want it to be as simple as possible with the least amount of wires, but I also want to understand WHY it is wired the way it is.

any help is appreciated, thanks
Jordan

Hi

Check out the wiring diagrams in the tech section - there is one for every build!

The bare minimum you need to make the bike run is:

- Alternator
Turns some of the mechanical power your engine is putting out into electrical power, but the power it produces isn't in a form you can use directly. It's pulsating AC and you want nice smooth DC.

- Rectifier and Regulator (often combined in one unit)
The little wallwarts and power adapters that come with every cellphone, laptop etc? They change your household AC power into DC power. The rectifier in the bike does the same thing. The regulator makes sure you're getting the right amount of that DC voltage. Too much and you'd blow light bulbs, too little and the spark plug wouldn't fire reliably.

- Battery (or capacitor)
Smooths out the DC voltage coming from the rectifier/regulator. A battery stores some as well so the system doesn't go dead when the engine isn't running.

- Ignition controller (pamco in your case)
Watches the rotation of either the crank or the cam looking for the right time to fire the spark. At the right moment it sends power into the ignition coils.

- Coils
The electrical system in the bike is 12 volts. That's fine for running light bulbs but it's not going to do anything for a spark plug. The ignition coil steps the 12 volts way up to more than 12,000 volts.

- Spark Plugs
The reason you need all of the above. As the boss said "...You can't light a fire without a spark". The spark plugs need just the right amount of electricity at just the right time or the bike won't run and all the other parts are there to make sure the spark plugs get what they need when they need it.


You usually have a key or switch to turn the ignition system on or off, at least one fuse to protect it in case it gets shorted out, and some number of lights depending on your local laws, but you asked for the bare minimum and that's it above.

As far as I can tell, the only wires that are on the engine are the 6 wires coming from the electronic ignition unit and then a connector that comes from my engine, where does everything else come into play? the descriptions are very good and give me some insight into this electrical world

A stock 75 wouldn't have electronic ignition. There should be a harness comming from underneath the left engine cover. These are the alternator wires. These go to the rectifier and regulator. look here at post 6 first diagram...a good basic setup.

http://www.xs650.com/forum/showthread.php?t=61

These are the stock parts

http://www.xs650.com/forum/showthread.php?t=22345

I have the pamco pete electronic ignition, as I stated in my first post. The harness coming from the left side engine cover has one white connector on it, how do I plug both the rectifier and regulator into it?

That wiring diagram in post 6 seems to be exactly what I have, but where on the bike is the starter solenoid and what does it look like? (I do not have my starter installed so does that part of the diagram become obsolete anyway? If so, then I do not need the red wire running from the battery + to the starter solenoid and I do not need the white/red strip wire going to the starter solenoid, correct?)

Also, what is that little gray rectangle between the alternator and the rectifier? It is on an angle to the rectifier.

Are you using/do you have the stock charging system components? What alot of people do in your situation is just start over and make your own wiring harness. In the end it's just much easier and you have new wires instead of 35yr old wires and connectors. If you do this then just connect the wires together from the components as shown in the diagram.

The starter solenoid would have been under the right side cover. The main positive battery cable went to it. The red and red/white wires to the solenoid wouldn't be needed for kick only. There are alot of simple wiring diagrams out there, just pick one that fits your situation best.

The little gray box is your brushes on the alternator.

I already had planned on building the harness this weekend, I just wanted to make sure that I knew what I was doing before I just started hooking up wires.

The only thing not stock on the bike is the pamco electronic ignition, so I would assume that the charging system is stock. I ran low on funds and could not get the PMA during the rebuild.

Does this wiring harness look good? (I took a previous one and modified it) (The kill switch seems to only cut power to one cylinder, how do I wire it so that it kills power to both?)

That diagram looks like it will work fine. The ignition wiring looks a bit off, but I have not used a rephased ignition yet. Where the kill switch red wire goes to the ignition you have it go to one coil and the other coil gets it from the Pamco. That don't ;look quite right. Shouldn't the red wire from the kill switch go to both coils and the Pamco?
Leo

Yes, you are correct, I need another B+ to the other coil, I will update the diagram when I get out of class, wouldn't the electronic ignition then send the signal to both of the coils though? I will made the new diagram and then post it, it will make more sense on what the problem is.

I am still confused as to what connector is coming from the left side of my engine, it is one white connector

Ok the ignition does not send a signal to the coils. Power flows to the coils on the red wires, through the coils, out on the green wires to the ignition. To get the coils to fire the ignition grounds the green wire.
With the rephase you have two ignitions set 270 degrees apart. Each ignition is seperate from the other. They can't fire both coils at the same time. The connector coming from the left side of the engine is the the alternator wiring. The connecter should have thee white wires, a black, green and blue wire in it.
The three whites hook to the three whites of the rectifier. The black is ground, it hooks to the black from the regulator, the green is power to the brushes, it hooks to the green from the regulator.
Leo

XSLeo said:

Ok the ignition does not send a signal to the coils. Power flows to the coils on the red wires, through the coils, out on the green wires to the ignition.

Click to expand...

Current flows the other way, from ground up through the coils to the battery, but it doesn't matter. As long as the ignition unit can control when current flows through the coil and switch it off again at the right time you get what you need. It was normal to do the switching at the ground end of the coil, the points were there too.

Is this how it needs to be setup then?



With that diagram, the coils will always have power from my understanding, at least when the key is turned to "on". The power will not flow back through the red leads going to the electronic ignition and fry it?

I believe I am running the same coils that you are (my coils are green at least). I am looking at getting a new regulator and rectifier also, any suggestions? Will any of the ones on eBay work?

Also, where are the brushes? aren't those internal to the engine, on the alternator? How do I hook the green wire from the connector to the brushes?

your brushes are housed in the stator, under the round panel on the left side engine cover. should be 4 screws holding it all together.

JNizza92 said:

With that diagram, the coils will always have power from my understanding, at least when the key is turned to "on". The power will not flow back through the red leads going to the electronic ignition and fry it?

Click to expand...

This is maybe my fault for writing that the ignition "sends power into the coils" instead of getting into the details. That's not a technical description, you can't actually "send power" to anything but I was trying to simplify the situation.

You have two ideas here, voltage and current, and you only get power when both are present. The red wire brings a voltage to the coil. A voltage by itself is just a state of being, nothing is actively going on and no power (heat/work) takes place so the coil won't fry just because it's connected to the red wire. The ignition unit controls when current will flow through the coil by connecting the other end to ground. It only charges the coil for a short time before each spark event, the rest of the time the coil is "off". It's still connected to the battery voltage by that red wire but it lacks a path to ground to complete the circuit and get current flow so it's off.

One gotcha about the older mechanical ignition systems was the engine could come to rest at a point where the coil was "on" and actively charging. If you left your key in the run position the battery would discharge through the coil to ground. I don't know if the pamco works that way or not but Pete posts here frequently so he can answer that for you.

With the Pamco that I have you cannot leave your ignition "on" without the bike running or you will fry the coil. Make sure that the kill switch is in the off position when you are testing your wiring with the ignition "on" and the bike is not running.

So essentially the brushes are internal to the engine and I do not need to hook anything up to them because they are already all set?

Also, since the black wire from the harness hooks to the black wire from the regulator can't I just ground both of them separately?

What happened to the blue wire that XSLeo mentioned was in that connector?

Scrambled, can you go into a little bit more detail? I am slightly confused, I must be missing something.

So is this diagram correct? (The yellow rectangle represents the connector from the left side of the engine)

The brushes are not internal to the engine. They are behind the cover on the left side, but not actually in the engine. They are very simple to access and inspect. They have springs on them that push them into the rotor as they wear down. Anyone that is about 3/8ths or so should be changed.

looking at it from an electrical standpoint with respect to the connector coming from the left side of the engine, the brushes are internal and have nothing else that needs to be connected to them, except through the connector, correct?

correct on the brushes. The blue wire you were asking about goes to the neutral switch which is on top of the engine block under the carbs. Scrambled I believe was just telling you to keep your ignition off via kill switch if you are checking other parts of the wiring system with the key on and the bike not running as it will kill the Pamco.