Fixing Stators 2: Electric Boogaloo
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1965 Vespa SS180, 1963 Lambretta LI150
Joined: 05 Mar 2007
Posts: 6973
Location: Detroit, Michigan
Fri Aug 07, 2009 5:09 am quote
So, that picture i found of a smallframe stator gave me an idea, so i photoshopped it up for reference.



So, here we see the standard, serviceable points stator. I think a lot of people have the same problem i did, where a coil gets crimped or is shorting...and they go buy a whole new stator... because they don't realize how easy it is to just fix the one coil.

So.. there's everything labeled. The coil that's immediately to the left of the points is ( in every case i've seen so far ) the ignition feeder coil. This guy is connected on the left hand side to ground, and on the right it has a short wire that connects to the points right next to it, using that little flathead screw you can see on the points.

ALSO attached at that same screw-contact point on the points is a yellow wire that runs over to the condenser. IIRC, the condenser is basically a little capacitor that's acting as a filter for the system ( like a one way gate) , allowing electricity to flow ONE way ( to the spark plug ) but not allowing it to flow backward to the points. If you have a bad condenser, often times you can see a blue spark arcing across the points because electricity is able to backtrack from the HT coil all the way back to the points, and you're probably going to end up with corrosion much faster and the points will stop working ( i'm guessing on that ).

The other wire coming out of the condenser is RED, and it is just a long wire that runs up to your junction box, and to the HT coil on the back of the bike ( or your kill switch, if it's depressed )

So, that's a pretty easy process flow to imagine. The Feeder coil generates the initial electricity, the points determine when to create the spark based on your timing, the juice flows on to the condensor which acts as a one-way valve, and then on to your HT coil on the back of your bike, which takes a low voltage, high current signal and converts it to a high voltage, low current signal ( MDchanic, please correct me if i'm wrong ) which goes down your spark plug wire and across the plug - where the high voltage is able to jump the gap to ground and create a spark.

So, what do those other things do?

Well, the two remaining coils on this stator are both lighting coils. If your bike is non battery, you have 3 basic circuits for all of your accessories. One for Headlight and Taillight ( Yellow ) one for Brakelight ( blue ) and one for horn ( green ).

Those 3 circuits need juice generated for them, so they are split up in some way between these two coils. A certain amount of copper windings around each coil is needed to generate the proper amount of juice the circuit needs. Well, how do you get 3 circuits out of 2 coils? Easy - they are layered, and then isolated with some sort of insulating wrap.

I'm pretty sure on the picture above, the upper coil is ONLY the yellow circuit - it's doing all your headlight / taillight. The other coil has both blue and green wires coming out of it... so one of the sets of windings on the coil has a blue lead for the brakelight - then there's an insulating wrap put over it, then another set of windings for the green ( horn ) circuit.

The other end of all these windings HAS to go to ground.

Now, coils get old. They get hurt. The windings get loose or separate or whatever and you end up with a coil that's putting out WAY TOO MUCH ( or not enough ) juice.

For example, on my SS180, currently my YELLOW circuit is running way too hot, and putting out enough voltage that it's consistently burning out my taillight bulb. Why not the headlight bulb? I dunno, the taillight, being only a 5 watt bulb, is the weakest link and it's easy to fry. My headlight is blinding, though.

So, i ordered a replacement lighting coil for it, which contains both YELLOW and BLUE leads coming off of it. Is that correct? I dunno. If it's not i'll just clip the blue lead and only use the yellow. I'll let you know the results.

Last edited by Rover Eric on Fri Aug 07, 2009 5:14 am; edited 2 times in total
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1965 Vespa SS180, 1963 Lambretta LI150
Joined: 05 Mar 2007
Posts: 6973
Location: Detroit, Michigan
Fri Aug 07, 2009 5:12 am quote
How do you get the coils off? That's the easy part.

First off, notice how all three coils in the pic are just held on with screws? Pop off those two screws and they will just fall off.

You might have to undo their wire at the junction box, since many of these coils have their wires run directly to there.

And, like i said, remember that the other side of the coil needs to be grounded, so there's usually a tab or something on the other side of the coil that's meant to be placed under the screw when you tighten it down.


So.. if you have a circuit that's constantly blowing bulbs, try changing out your lighting coil, rather than throwing an inline regulator into the loop ( which is just putting a bandaid on the problem ).
Hooked
GS 160 /4
Joined: 01 Mar 2009
Posts: 402
Location: Maine, USA
Fri Aug 07, 2009 5:26 am quote
First, for comparison, here's a GS 160 with battery.

The coils, points, and condenser are labeled.

The "Points" label points to the points themselves.
Their connection screw is just to their left and above (with the dark yellow wire attached).
Their adjustment (clamp) screw is just above and a hair to the left.
The older ones also have an adjustment screw that positions the points before you tighten them down - this is immediately to the left, through the crook of the dark yellow wire.

You can see ground wires snaking out of the "counterclockwise" sides of the lighting cols, where they are screwed to the stator frame.

Both of the lighting coils have lighter yellow wires, which are soldered together (in parallel) on the little terminal board on the left.

The condenser is labelled in red.
In this picture, a previous owner has soldered the purple coil (-) wire to the condenser, whereas it should have a ring terminal end and be screwed to the points next to the dark yellow condenser wire.
The two connections are electrically the same, but this way, you have to have a soldering iron every time you want to change the points.

-----------------------------------------------------------------

Rover Eric, I am sorry to say that you made a few errors in your description of the non-battery system, one of which is actually important to understanding how it works and to troubleshooting it. I'll post on that shortly.

- Eric

GS 160 w Batt.jpg

Addicted
1980 P200e, 1956 ACMA, 1979 P200e, 1974 Ciao
Joined: 04 Jun 2009
Posts: 766
Location: Ithaca, NY
Fri Aug 07, 2009 7:24 am quote
Guys,

I just want to say "Wow, thanks!" This is great stuff! I'm about to replace my stator in my P200e, so this is really timely.

Mike
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1965 Vespa SS180, 1963 Lambretta LI150
Joined: 05 Mar 2007
Posts: 6973
Location: Detroit, Michigan
Fri Aug 07, 2009 7:27 am quote
Well, your P200 is a different beast, with the electronic ignition and all.

The coils on those tend to be riveted or more permanently attached, versus the old ones which can be removed.

Still, if you get something out of this, then awesome.
Hooked
GS 160 /4
Joined: 01 Mar 2009
Posts: 402
Location: Maine, USA
Fri Aug 07, 2009 8:18 am quote
Okay, so I modified a ScooterHelp diagram to break the non-battery electrical system into three separate parts, one for each of its separate coils.

I'll go through each of them to show how they work.

First, though, I should just mention that the function that Rover Eric described for the condenser actually describes a diode. The condenser in this case actually acts more like a cushion, or that twisty piece of pipe attached to the hot water heater that prevents the pipes from hammering if you turn off the water too fast. When the points are closed and current (about 6VDC in this case) is flowing through them, as they begin to open, the initial opening will be small enough for the 6V to jump the gap, beginning to create a spark (and beginning to ionize the air, which lowers its resistance, making the current flow more easily). As the points open more and the gap widens, the current will continue to flow through this gap for as long as it can.
The condenser provides a sort of a second area for that current to go to, so that it stops jumping the points gap earlier, so that, over time, the points are not eroded away by a larger spark.
(Electrical engineers can jump in any time and start talking about the tuned resonance of the circuit, but only if they can put it in terms of Goths and the Mall).

Second, I am not certain about Eric's description of coil failure modes.
As far as I know, either a winding breaks, causing an open circuit and no juice, OR insulation breaks down, causing windings to be "skipped over" by the current, resulting in LESS voltage being produced. I may be way wrong here, but I don't know of a way that a failed coil can produce MORE voltage than it should. Sorry, Eric, that means that if I'm right, a new coil won't fix your problem.

Third, not all of the coils connect to ground in these bikes, which is why it's confusing, as you'll see...

Finally, a note on unregulated alternator systems of variable speed:
Your car has an alternator. It makes AC current just like these, with 2 differences:
    The AC is rectified into DC before it leaves the alternator
    The voltage is regulated by varying the voltage in an electromagnetic rotor (the rotor on your Vespa is a permanent magnet)

Because of these differences, your Vespa alternator DOES NOT make steady voltage OR current. These both vary with the speed and load of the alternator. The faster it goes, the hight the output, and the greater the voltage and the current. The higher the load (or, the lower the resistance across the coil), the lower the voltage, but the higher the current.
The engineers who designed this system designed it with certain expectations, such as
    The engine will not rev above about 7,000 RPM, and
    There will always be a certain load (certain light bulbs, etc. of certain values) on the system.

It is designed to give about 6 volts within those parameters, but if they are changed, such as if a bulb blows out, it will not do so.
For example, if one of the three parallel-connected light bulbs in the brake / taillight circuit blows, the load decreases (resistance increases), and so the voltage increases. The increased voltage pushes more current through the filaments of the remaining light bulbs, heating them excessively, and causing them to burn out as well.
So, when you look at these diagrams, you need the se the voltage and current flowing through them not as static numbers, but as dynamic ones that are constantly changing.

------------------------------------------------------------------

Looking at the diagrams, we first encounter the ignition coil.
    •This coil should be making about 6VDC when the motor is turning, which feeds the HT coil primary through the red wire. (it is possible that this coil actually makes AC, but for our purposes, it's safer to assume DC - I don't have one to test)
    •The HT coil "steps up" this 6V to something like 15,000V for the spark plug.
    •DC cannot be stepped up by transformers (like the HT coil) because transformers need CHANGING voltage in order to work,
    •SO the points open and close, creating a pulsed DC, and the spark is created at the instant that the points OPEN.
    •The operation of the condenser is described in my first point above.
    •The kill switch simply sends the coil current directly to ground, so that, following the path of least resistance, it no longer flows through the HT coil and the spark stops, killing the motor.


    •SO, we have current coming from the red wire of the ignition coil, traveling through the HT coil primary winding to ground, then back through ground to the ignition coil again.
    •At the same time, this current is shunted directly to ground (not going through the HT coil anymore) once every revolution by the points, then reconnected again.
    •The condenser is connected between the points and ground as a cushion.
    •The same wire that connects to the HT coil, the points, and the condenser goes to the kill switch, so you cna stop the motor by grounding the ignition.


------------------------------------------------------------------

Next we have the diagram of the horn / headlight circuit.

I can't perfectly describe this because I don't have a headlight switch or a good diagram of one in front of me, but I believe I've got the idea.

    •In this case, the coil produces about 6VAC, which comes out through the green wire, and flows to the handlebar switch, from which it is also sent to the horn.
    •There is a wire from the horn back to the handlebar switch, where there is a switch that connects it to ground when you press the horn button, allowing the current to flow back to the coil through ground, thus sounding the horn.
    •Also in the handlebar switch, there is a "headlight on / off" switch which connects the green wire to the "high / low beam" switch when you turn the lights on.
    •Finally, there is the "high / low beam" switch, which sends the current to either the high or low beam filament in the headlight bulb, from which it then returns to the coil through ground, thus lighting the headlight.


------------------------------------------------------------------

Finally, we have the diagram of the brake / taillight coil.

This is the bitchiest one to understand, and it is the only one that does not have one side connected to ground.

This coil also makes about 6VAC.
For the sake of argument, we will assume that the current is coming "Out" through the Yellow wire and going "In" through the Blue, though, in reality, it doesn't go in any one particular direction (true for the previous descriptions as well).

    •SO, the current comes out through the yellow wire and travels to the taillight, "pilot" light, and speedo bulb, all at the same time. As far as I can tell, there's no switch for these, but, as I said before, I don't have a headlight switch or a good diagram of one in front of me.
    •The current flows through each of these three bulbs to ground (maybe I should have erased the black wires and just made "ground" symbols. maybe I will later...).
    •Once at "Ground" level, it DOES NOT flow back to the coil, which IS NOT grounded.
    •Instead, it flows FROM GROUND through the (normally closed) brake light switch TO the Blue wire, which returns it to the coil, completing the circuit.
    •(It DOES NOT flow through the brake light filament, as it has a path of lesser resistance, the closed brake light switch, to go through instead).
    •NOW, when you step on the rear brake, you OPEN the brake light switch, STOPPING the flow of current through it, and giving the current nowhere else to go on its way back to the blue wire and the coil, EXCEPT through the filament of the brake light bulb, so all of the current that has been powering the pilot bulb, the taillight bulb, and the speedo bulb (all of these three in parallel with each other), now flows through the brake light bulb (in series with the other three) to the coil, lighting the brake light bulb as well. Yes, this would be expected to instantaneously HALVE the voltage going to all four light bulbs, BUT you have just increased the resistance (substituted a light bulb filament for a closed switch), so the system voltage goes up, making up for the expected decrease.


------------------------------------------------------------------

A (really) final note:

Just because these circuits are designed to be separate, that does not mean that, because of worn insulation or similar problems, they cannot become ACCIDENTALLY connected together, releasing all manner of gremlins, and requiring looking at the electrical system as whole, rather than as a series of separate parts.

- Eric

Non-Batt Ignition.jpg
Ignition
Thanks to ScooterHelp

Non Batt Horn & Headlight.jpg
Horn & Headlight
Thanks to ScooterHelp

Non Batt Brake & Tail.jpg
Brake & Tail
Thanks to ScooterHelp



Last edited by MDchanic on Fri Aug 07, 2009 9:40 am; edited 3 times in total
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1965 Vespa SS180, 1963 Lambretta LI150
Joined: 05 Mar 2007
Posts: 6973
Location: Detroit, Michigan
Fri Aug 07, 2009 8:26 am quote
hmmm

looking at your last diagram, i'm wondering if maybe the fact that my bike doesn't have a pilot light could be causing the taillight to pop.....since there's too much juice going through the 5 watt without the corresponding 3 watt to divert some of it.


I have to troubleshoot a weird thing that's happened since i swapped taillights on friday.

Previously all my lights worked fine ( minus the taillight blowing ). Now, whenever i step on the brake pedal, rather than the brakelight going on, the taillight goes off. Brakelight never comes on.
I guess i need to go back there and check my ground.


With regard to how a shorting coil could put out TOO MUCH voltage...i don't know myself. But i've seen brakelight circuits dumping like 40 volts before.... ones that were functioning normally before that. a replaced stator fixed the problem. *shrug*
Hooked
GS 160 /4
Joined: 01 Mar 2009
Posts: 402
Location: Maine, USA
Fri Aug 07, 2009 8:40 am quote
Rover Eric wrote:
Now, whenever i step on the brake pedal, rather than the brakelight going on, the taillight goes off. Brakelight never comes on.
If your brake light isn't "there" (blown filament, bad ground, bad "hot" connection), when you step on the brake, the circuit returning current to the coil through the Blue wire is broken, but it is not replaced by the filament of the brake light bulb, so all bulbs go out until you let up on the pedal.

This may have been their way giving you a warning of a blown brake light - you could theoretically see it when your speedo light goes out (yeah, right).

And your warning of a blown taillight is that all of the other bulbs blow.

- Eric
Hooked
GS 160 /4
Joined: 01 Mar 2009
Posts: 402
Location: Maine, USA
Fri Aug 07, 2009 9:20 am quote
Note: I just added these edits to my treatise above.
MDchanic wrote:
Finally, a note on unregulated alternator systems of variable speed:
Your car has an alternator. It makes AC current just like these, with 2 differences:
    The AC is rectified into DC before it leaves the alternator
    The voltage is regulated by varying the voltage in an electromagnetic rotor (the rotor on your Vespa is a permanent magnet)

Because of these differences, your Vespa alternator DOES NOT make steady voltage OR current. These both vary with the speed and load of the alternator. The faster it goes, the hight the output, and the greater the voltage and the current. The higher the load (or, the lower the resistance across the coil), the lower the voltage, but the higher the current.
The engineers who designed this system designed it with certain expectations, such as
    The engine will not rev above about 7,000 RPM, and
    There will always be a certain load (certain light bulbs, etc. of certain values) on the system.

It is designed to give about 6 volts within those parameters, but if they are changes, such as if a bulb blows out, it will not do so.
For example, if one of the three parallel-connected light bulbs in the brake / taillight circuit blows, the load decreases (resistance increases), and so the voltage increases. The increased voltage pushes more current through the filaments of the remaining light bulbs, heating them excessively, and causing them to burn out as well.
So, when you look at these diagrams, you need the se the voltage and current flowing through them not as static numbers, but as dynamic ones that are constantly changing.
MDchanic wrote:
Yes, this would be expected to instantaneously HALVE the voltage going to all four light bulbs, BUT you have just increased the resistance (substituted a light bulb filament for a closed switch), so the system voltage goes up, making up for the expected decrease.
Hooked
Super 150
Joined: 19 May 2009
Posts: 292
Location: Southeast, GA
Fri Aug 07, 2009 9:33 am quote
Great job Eric and Eric. It's the people like you guys who ask these question just for fun that make life easier for everybody. Thanks for taking the time to look through this stuff and then let everybody know whenever you figure out cool stuff like this.

Oh, and here's some folks that also wanted to say thanks, in honor of the name of this thread.

breakin.jpg

Moderator
1965 Vespa SS180, 1963 Lambretta LI150
Joined: 05 Mar 2007
Posts: 6973
Location: Detroit, Michigan
Fri Aug 07, 2009 9:36 am quote
Thanks to the other Eric for helping me with my own understanding of it. You've clarified a lot of points that were guesses or grey areas on my part.
Molto Verboso
79 P200e, 81 100 Sport
Joined: 23 Sep 2006
Posts: 1443
Location: Iowa
Fri Aug 07, 2009 9:57 am quote
I was hoping someone would post a pic of Turbo and Ozone!
Addicted
'78 Super 150 Mk II ported DR177, banded clutch, ASC Big Bore
Joined: 14 Jul 2008
Posts: 664
Location: Ottawa, ON, Canada
Fri Aug 07, 2009 4:03 pm quote
I've had a real headache with stators of late; I bought a new one and the backing plate ended up being marginally too thick and the flywheel rubbed through some of the insulation and into the wiring (though it ran like a top before that!).

So I brought it to a machinist who ground the backing plate down to the height of the original (and Scooter Parts Direct reimbursed me for the cost of that -- top notch customer service!), but in the process he gently nicked two of the new coils (I had been lazy and not taken them off since I figured he was only going to work on the back). Arghhh! Followed by (@#$*&$%*( !!! I knew it couldn't be good to run them like that, since the insulation might be affected and coils touch, or one be so thin as to affect its viability.

I ended up making an unholy mix of the new stator plate (which I wanted to keep since it had a better system for points gap adjustment than the old one) with one good new coil, and two of the old coils. It's a bit of a mixed bag since the ignition coil is one of the old ones and I had been having weak spark...



Here's a pic of the OLD one, which I'm keeping for spare parts (I don't have the black ground lead attached in this pic). Note that with BOTH systems the ignition feeder coil is directly connected to the coil next to it (on the same side of the points), as if one coil ran into the other (and protected by shrink tubing). While the wiring diagram shows just one lead coming off the ignition coil, there must actually be TWO coils involved (perhaps to generate enough current required for the spark plug).

The condensor yellow wire is connected with the ignition coil at the points, and the condensor's red wire naturally is the igntion lead, connecting to the kill switch wire in the junction box.

Here's the really wonky bit: with the old stator, before an engine rebuild, I had a reliable halogen 35/35W halogen headlight, a working tail light, and a brake light that never popped unless the headlight wiring became disconnected. The horn and kill switch were fine, too. I had no speedo bulb nor a pilot. The system was just fine...

During the engine rebuild I noticed a quite frayed black wire (presumably ground), so I replaced it, and solidified some other connections but didn't change anything else apart from the black lead. When I went to start up after the rebuild, the same original connections in the junction box didn't work any more... FARK! Playing around with the connections in the box, I could have headlight OR brake light, but not both, and no tail light at all.

Eventually I got a new stator and hoped the new coils would solve wiring/ignition/lighting issues. The engine ran well (likely from the new coils, as I had a new condensor and points in the old stator after the rebuild). Still no dice with 100% working lights, though. Then the flywheel rubbed enough into the wiring to just totally cut ignition during a commute (as per above) and I had to make this bodge from two different stators.

After f**king around a long time with a volt meter (and getting some good readings, like 6v at ignition, and some alarming ones like 18v at idle on another lead), depending on what was connected, in desperation I finally just tried whatever connections I could concoct, and through enough cursing in Italian, venerating St. Christopher, and a sacrifice or two to the Roman pantheon, I got both the headlight and brake light to work (and at the same time - yay!). That's good enough for me, so I'm leaving it, and it's been working for a good month or so. Here's the weird thing I just noticed yesterday, though: the handlebar switch cover is slightly warm to the touch. I had never noticed it before as I always ride with gloves on. Something weird is going on there... there must be a short within the box itself. I don't have the energy this season to rewire a whole new harness, but we'll see for next year. At that point I might give up on the nearly useless points system, too, as it's been nothing but problematic... (very finicky about gap settings, and then they change as the cam wears on the actuator of the points).

Wow - that was a diatribe!

I've lost some top end power and struggle up hills that I could do happily and with power in June while the all new stator was still in virginal condition. It could be weak spark (whatever is causing that: coils, condensor, points, whatever), or I've also discovered a leak (blowby) at the cylinder head on my 3 port jug. I had always thought the oil was a leak at the exhaust header, but apparently not. Since this also had been the case in June, I figure that's not the cause of lack of power, but it must affect compression (tested at about 100PSI yesterday morning).

To top it all off, I broke a clutch cable on a ride this afternoon. I rode it home just fine, but it was the icing on the cake.

Now I'm going to go and yell at my kids and wife out of the blue to get rid of frustration.
nothing at all
Joined: 14 Nov 2008
Posts: 9657
Location: westla
Fri Aug 07, 2009 10:22 pm quote
after all this thread i really miss the goth circuits in the mall
Hooked
bunch "o" bikes
Joined: 14 Jun 2008
Posts: 226
Location: Trail, B.C, Canada
Fri Aug 07, 2009 11:38 pm quote
phaetn wrote:


Note that with BOTH systems the ignition feeder coil is directly connected to the coil next to it (on the same side of the points), as if one coil ran into the other (and protected by shrink tubing). While the wiring diagram shows just one lead coming off the ignition coil, there must actually be TWO coils involved (perhaps to generate enough current required for the spark plug).
I hate to tell you this, but no vespa (other than the GS,it may be argued, with the battery assisted spark bullshit ) EVER used 2 coils in series for ignition
your bike has
1 for ignition
2 for lighting
I would be doing a little re-wiring if I were you
sean s
Addicted
'78 Super 150 Mk II ported DR177, banded clutch, ASC Big Bore
Joined: 14 Jul 2008
Posts: 664
Location: Ottawa, ON, Canada
Sat Aug 08, 2009 3:18 am quote
sean s wrote:
I hate to tell you this, but no vespa (other than the GS,it may be argued, with the battery assisted spark bullshit ) EVER used 2 coils in series for ignition
your bike has
1 for ignition
2 for lighting
I would be doing a little re-wiring if I were you
sean s
Are you sure about this? I have to respectfully disagree: My Super (VBC) was like this initially; even if it was a nightmarish electrical bodge, a brand new stator suitable for VNA, VNB, VBA, VBB, VLA, VLB, VBC that I bought was also like this; finally, looking at the pic Eric used, above, you can see two coils in series (look at the path of the red arrow indicating the woodruff key: that thin yellow wire that it intersects is joining the two coils, the second of which goes directly to the points (and hence is ignition); the actual yellow wire for lighting is from the coil at the top (it's thicker and you can see the yellow insulation actually connecting on the coil and dropping down) and it's routed so it comes out below by the flechette of the red arrow -- don't confuse it with the yellow lead of the condensor which is right beside it and snakes its way back the the points.

Perhaps this is unique to 6v systems, or a two wire condensor system, whereas others don't have coils in series [shrug]. I can't speak for the others, but I've can speak to the ones I have and have spent at least a few hours working on, taking them totally apart and putting them back together.

Note that an electrical diagram wouldn't necessarily show the coils as being in series, as the diagrams typically just show the placement of coloured leads that come off the coils to get routed elsewhere, but not necessarily an internal connection.

I suppose a coil may be considered as "lighting" if it only has one lead that you have to connect at the junction box, but it could (as mine does) also have a separate coil wrapping that connects it to another coil, which then goes to the points, thereby serving two functions (both lighting and ignition). This latter function isn't "labelled" since it doesn't have a lead coming off it that you have to worry about connecting anywhere.

By the way, have I mentioned how much I hate electrical troubleshooting.
Hooked
GS 160 /4
Joined: 01 Mar 2009
Posts: 402
Location: Maine, USA
Sat Aug 08, 2009 4:40 am quote
sean s wrote:
I hate to tell you this, but no vespa (other than the GS,it may be argued, with the battery assisted spark bullshit) EVER used 2 coils in series for ignition
Don't wish to sound pedantic, but the GS has 1 for ignition / battery, 2 in parallel for lighting.

I'm still trying to wrap my brain around Phaetn's problems.

Trouble is that I'm not convinced that his is an original setup, so I'm not sure whether I can just look up a diagram.

Gotta work today. I'll think about it.

All this stuff is is a big symbolic logic problem - you've just got to know enough details to figure out the unknowns.

- Eric
Addicted
'78 Super 150 Mk II ported DR177, banded clutch, ASC Big Bore
Joined: 14 Jul 2008
Posts: 664
Location: Ottawa, ON, Canada
Sat Aug 08, 2009 5:25 am quote
Yeah, mine might be a weird setup, indeed, but -- at least for ignition -- it works out of the box with a new 6V stator. Note this pic from Scooter Parts Direct:



It also clearly shows that the coil right above the condensor is connected in series with the coil next to it, which is beside the points and doesn't have any other leads coming off it to go to the junction box (they're connected under the black shrink tubing).

Note that on the left side of the first coil there's a soldered connection to ground on a tab under the screw, while in the right side there's a black wire, leading to a ground lead connection for the junction box.

As per my own previous pic, this coil also has a green lead coming off of it (for the horn) and, through a process of Goths in a mall, to the headlight (see following wiring diagram):


That accounts for all five leads in my junction box: Green (horn and headlight) and Black (ground) from one coil (the black not actually affixing to the coil, but just the screw); blue (tail) and yellow (brake); while red heading to the HT Coil comes from the condensor.

I'm quite sure that some of my problems are either from a short in the harness or perhaps in the handlebar switch. Either way, I'm not too worried about it as I have a working headlight and brake light, which is all I'm worried about, apart from ignition. I've foregone a tailight and just installed a little magnetic flashing LED under the lens which I turn on when it gets dark.

As for the ignition, I'm just going to order some new coils and see if that helps. It was running very well before the flywheel rubbed, so I don't think my poor top end performance is from blowby at the head, as I already had a leak from there before then....
Moderator
1965 Vespa SS180, 1963 Lambretta LI150
Joined: 05 Mar 2007
Posts: 6973
Location: Detroit, Michigan
Sun Aug 09, 2009 5:36 am quote
Nice diagram, Phaetn.

Yesterday i looked at both my speedo and pilot bulb...somewhat surprised by the fact they had both blown... the pilot bulb i had in there was 5 watt to begin with .. ( not 3, as specified ) so that might have explained what caused the first taillight to blow... and then every one after that because it didn't have a fresh pilot bulb to balance the load.

the speedo bulb was shot as well ... and my brakelight bulb was dead to boot... so that would explain some things.

I realize this is basic troubleshooting - but i was so busy riding i hadn't had any time to take off the lenses and look at the bulbs to see what was still intact. I'll be more mindful in the future.
nothing at all
Joined: 14 Nov 2008
Posts: 9657
Location: westla
Sun Aug 09, 2009 6:26 am quote
dude, she's hot

goth-makeup.jpg

Hooked
GS 160 /4
Joined: 01 Mar 2009
Posts: 402
Location: Maine, USA
Sun Aug 09, 2009 6:42 am quote
Rover Eric wrote:
... the pilot bulb i had in there was 5 watt to begin with .. ( not 3, as specified ) so that might have explained what caused the first taillight to blow...
Eric,

Actually, it's the opposite.

You can imagine the unregulated alternator system
(but NOT most normal electrical systems, whose voltages cannot exceed their nominal value)
as one of those pesky midwestern rivers [of Goths?] in the spring.
The river will rise until it runs over its banks, and that's as high as it will get.
If the way downriver is clear, it may not overflow its banks, because the water can flow downstream.
If the way downriver is partly blocked, though, say, by tangles of trees or SUV's that tried to ford it, then the level will rise.
If the blockage is enough, it will continue to rise until it submerges Cleveland.
All of this is worse during flood season, and better in the dry season, because there's less water coming downriver.

On your SS, the season is analogous to the engine's speed - the faster the motor is turning, the more water is flowing.
The blockages in the river are the various light bulbs, etc that are connected in the circuit,
BUT remember that the MORE current a given item draws (the higher the wattage), the LESS resistance it presents to the flow.
Therefore, in this circuit,
HIGHER WATTAGE bulbs will provide more protection to the other bulbs, by bleeding off more excess current,
while LOWER WATTAGE bulbs will make high-voltage peaks at high RPM's more likely.

This is the opposite of what we are all trained to believe - that too high a draw will overtax the system and cause melted wires, etc. The truth is, that the system CAN'T make enough current to melt wires (at least mine can't - I accidentally ran it with both lighting coils shorted to ground for a long time - no harm done), so that's not what we need to worry about.

I'd stick with the 5W bulb, and, in general, use the higher-wattage options whenever you have a choice in bulbs. It will help protect the other bulbs in the event that one burns out.

- Eric
nothing at all
Joined: 14 Nov 2008
Posts: 9657
Location: westla
Sun Aug 09, 2009 6:50 am quote
i run 12 volt bulbs in my et3 and they don't blow now

when i put 6's in i have problems at speed
Hooked
bunch "o" bikes
Joined: 14 Jun 2008
Posts: 226
Location: Trail, B.C, Canada
Sun Aug 09, 2009 11:32 am quote
Well shit...Fuckin scooters..
not one of my box o stators nor any I've ever worked on uses this sort of setup.
That yellow wire from your ignition coil HAS to go to ground. If the 2 coils shared windings, then every time you beeped the horn or turned on the headlight, the motor would die.
Fuckin scooters
Now i have to find one of thoes stators and take it appart.
sean s
Addicted
'78 Super 150 Mk II ported DR177, banded clutch, ASC Big Bore
Joined: 14 Jul 2008
Posts: 664
Location: Ottawa, ON, Canada
Sun Aug 09, 2009 4:07 pm quote
sean s wrote:
Well shit...Fuckin scooters..
not one of my box o stators nor any I've ever worked on uses this sort of setup.
That yellow wire from your ignition coil HAS to go to ground. If the 2 coils shared windings, then every time you beeped the horn or turned on the headlight, the motor would die.
Fuckin scooters
Now i have to find one of thoes stators and take it appart.
sean s
I think it's highly, highly likely that there are two separate windings within the same coil. The green one goes off to headlight/horn, while the yellow one is quite separate and goes in series to the ignition coil beside it -- it would ground eventually via the spark plug, of course. I can guarantee that they're connected, as I've actually had the two coils apart at one point and resoldered them.

RoverEric, re wattages: what MDchanic says makes total sense. If you're routinely blowing bulbs one solution is to go UP in wattage if there's a particular problem. That might be only a band-aid, but it's a really good one. Unlike in a house light, however, where higher wattage means brighter, in this case it can actually cause dimming

By way of example: I had a 6V 5W festoon tail light that was okay at idle, but would pop at even the slightest revs. A 6V 10W festoon was a wee bit dimmer, but was generally okay for a few days' worth of riding, even at revs, but would eventually blow. (Given that I don't have the .6W speedo bulb in the circuit the brake is taking all the load.) I consciously didn't downshift as aggressively as I normally do to try to protect the bulb. A 6V 15W festoon was just way too dim -- really just a dull glow, and even at that it would take a moment or two after the brake was applied to glow. It was too weak to even be seen through the red lens.

Through a small error in shipping, I ended up getting a 12V 10W festoon instead of a 6V and decided tried it out. Happily, it has gone for weeks without blowing (unlike the 6V counterpart) and is actually a little brighter, so it's the best of both worlds.

My headlight is still a 6V 25/25 halogen, however, and in a really weird condition actually BRIGHTENS slightly as the brake light comes on. Go figure! Oh yes, if I honk the regular strangled duck horn the headlight basically flickers and goes out until I stop pressing the horn button; it can even go out if the horn button is twisted in its housing and the horn isn't sounding, so clearly there's a problem within the handlebar switch itself (confirmed by the fact that it also gets warm).

All this lighting is separate from the ignition, so as long as it's working I don't worry too much about whether or not it's a spec wattage or voltage It's "balanced" according to the harness and electrical conditions I have. One winter I may put in a new harness, but then should probably also get a new (properly magnetized) flywheel and all new coils so that everything is ship-shape.
Hooked
bunch "o" bikes
Joined: 14 Jun 2008
Posts: 226
Location: Trail, B.C, Canada
Sun Aug 09, 2009 9:48 pm quote
Phaetn and anyone else who likes to fuk with wiring,
While looking for that stator that I've never come across (and I have 2 of the bikes that are supposed to have it), I found this, which indeed, shows the yellow wire from the ignition coil to a secondary winding on the lighting coil.
I still dont know why they tried this but if you have ignition problems you'll have to replace both coils to troubleshoot.
This site is a fantastic read and it also confirms my belief that the VS5 was wired by satan.
http://www.vespa-klub.dk/EL_english.HTM

11.jpg

Molto Verboso
Joined: 31 May 2009
Posts: 1220
Location: NC, USA
Mon Aug 10, 2009 2:02 am quote
US 1979 P125X stator, scoot had 1040 miles, taken recently, as was from factory:



The condenser is pressed in, and the wires soldered to it. A new condenser for it comes with no wires. I will not be unsoldering those wires unless absolutely necessary. I like the way it looks.

I am new to Vespas, but have seen lots of other stator systems. Until looking at this thread, I could always rely on the oddball looking stator being for ignition. Usually with finer wire, more turns, often wrapped in paper or tape, maybe slightly different color. One ignition coil wire to the points, the other wire to ground on points type.

While the points are closed, current begins flowing when the magnet passes by, and a field builds around the stator ignition coil. When the points open, that field collapses. That rapidly collapsing field, called an inductive kick, is what pulses the external ignition coil, which steps it up to spark plug voltage.

That inductive kick, or pulse, is partly what the capacitor has to take away from the opening points to keep from burning them. You can feel that kick if you accidently touch the wire to the external coil, or the kill switch wire while cranking or running. It causes you to curse and dance slightly less than the voltage headed to the spark plug.

That inductive kick collapsing through a coil must be strong enough to feed the external coil to the spark plug. It MAY be that by series connecting two coils, it helps boost that kick. I don't really know. Since the coils in some of the pictures above don't show finer wire, or more turns to give a higher ignition voltage, MAYBE the series connection is for that.

Excuse the rambling.
Member
1964 150 ?
Joined: 25 Aug 2009
Posts: 6
Location: Baltimore Maryland
Tue Sep 01, 2009 2:58 am quote
Checking voltage
I have read the post and have a ? . I have no brake lights and no running lights but horn works and kill switch works. I have tried to read 6 volts dc at the terminal location with a multimeter with the red lead of the meter to the bule connection and the black led to ground and only get about 2 volts dc, would this suggest that one of my lighting coils is failing or needs replaced?
Moderator
1965 Vespa SS180, 1963 Lambretta LI150
Joined: 05 Mar 2007
Posts: 6973
Location: Detroit, Michigan
Tue Sep 01, 2009 4:36 am quote
DC ... on a 1964? Do you have a GL150 or some other weird DC bike from that time ?

Regardless of your bike model you will NOT get DC voltage off the stator... period. Only volts AC ... the only time you get DC voltage on a scooter is when you have wires running off your stator and going to a rectifier ... THEN you can measure the volts DC coming out of that.
Hooked
GS 160 /4
Joined: 01 Mar 2009
Posts: 402
Location: Maine, USA
Tue Sep 01, 2009 4:42 am quote
Re: Checking voltage
Hank1968 wrote:
I have read the post and have a ? . I have no brake lights and no running lights but horn works and kill switch works. I have tried to read 6 volts dc at the terminal location with a multimeter with the red lead of the meter to the bule connection and the black led to ground and only get about 2 volts dc, would this suggest that one of my lighting coils is failing or needs replaced?
You should have voltage between yellow and blue.
If so, then check bulbs, connections, and brake light switch (closed when pedal UP, open when pedal depressed).
Use the 3rd diagram in my post WAY above to see what is connected to what from the blue, yellow and black wires.
If you want, you can disconnect the yellow and blue coil wires at the terminal block and connect a 6V battery, so you can test voltages with the motor off,
or, you can just use an ohm meter (AC horn won't work on DC though).
Beware of corrosion at light sockets and any "repairs" made by previous owners.

- Eric
Member
1964 150 ?
Joined: 25 Aug 2009
Posts: 6
Location: Baltimore Maryland
Tue Sep 01, 2009 4:53 am quote
Thanks Eric, so if I set the meter to AC volts I should read 6 or more volts when I connect one side to say blue terimal and the other side to ground and the same with the yellow. If voltage is low or none then would I have a bad lighting coil. If I connect a 6 volt battery to the brake light circuit whne the engine is not running then my brake light works as it should, its just when the engine is running I have no lights in the back which leds me to beleive that the coil is bad or weak.

Thanks
Moderator
1965 Vespa SS180, 1963 Lambretta LI150
Joined: 05 Mar 2007
Posts: 6973
Location: Detroit, Michigan
Tue Sep 01, 2009 4:59 am quote
on your junction box.... on the engine ... if you unhook your wiring harness from it, and just touch the red lead of your Multimeter to the yellow wire coming out of your engine ...and the black lead on the multimeter to ground... it should read like +/-6VAC, depending on the RPM of your engine.

Same with the blue lead.

same with the green lead.

When you hook them up to the actual yellow and blue and green circuits on your bike is when your yellow and blue might have problems. You need to make sure you have proper 6v bulbs of the correct wattage in EVERY socket... that includes your speedo bulb, your pilot bulb under the headlight, the headlight bulb, tailight and brakelight bulbs.

If you have problems with them working, you likely have a ground problem somewhere.
Hooked
GS 160 /4
Joined: 01 Mar 2009
Posts: 402
Location: Maine, USA
Tue Sep 01, 2009 5:36 am quote
Hank1968 wrote:
Thanks Eric, so if I set the meter to AC volts I should read 6 or more volts when I connect one side to say blue terimal and the other side to ground and the same with the yellow. If voltage is low or none then would I have a bad lighting coil. If I connect a 6 volt battery to the brake light circuit whne the engine is not running then my brake light works as it should, its just when the engine is running I have no lights in the back which leds me to beleive that the coil is bad or weak.
No.

You set to AC Volts and touch one lead to the yellow wire on the terminal block, and one to the blue wire. These are the 2 wires on the brake / tail / speedo light circuit coil. Neither one is grounded. If that coil is giving juice, then you've got to be sure everything else is connected properly and that there is no corrosion.

Take a look at the circuit - I will repost my description of it thus:
MDchanic wrote:
Finally, we have the diagram of the brake / taillight coil.

This is the bitchiest one to understand, and it is the only one that does not have one side connected to ground.

This coil also makes about 6VAC.
For the sake of argument, we will assume that the current is coming "Out" through the Yellow wire and going "In" through the Blue, though, in reality, it doesn't go in any one particular direction (true for the previous descriptions as well).

    •SO, the current comes out through the yellow wire and travels to the taillight, "pilot" light, and speedo bulb, all at the same time. As far as I can tell, there's no switch for these, but, as I said before, I don't have a headlight switch or a good diagram of one in front of me.
    •The current flows through each of these three bulbs to ground (maybe I should have erased the black wires and just made "ground" symbols. maybe I will later...).
    •Once at "Ground" level, it DOES NOT flow back to the coil, which IS NOT grounded.
    •Instead, it flows FROM GROUND through the (normally closed) brake light switch TO the Blue wire, which returns it to the coil, completing the circuit.
    •(It DOES NOT flow through the brake light filament, as it has a path of lesser resistance, the closed brake light switch, to go through instead).
    •NOW, when you step on the rear brake, you OPEN the brake light switch, STOPPING the flow of current through it, and giving the current nowhere else to go on its way back to the blue wire and the coil, EXCEPT through the filament of the brake light bulb, so all of the current that has been powering the pilot bulb, the taillight bulb, and the speedo bulb (all of these three in parallel with each other), now flows through the brake light bulb (in series with the other three) to the coil, lighting the brake light bulb as well. Yes, this would be expected to instantaneously HALVE the voltage going to all four light bulbs, BUT you have just increased the resistance (substituted a light bulb filament for a closed switch), so the system voltage goes up, making up for the expected decrease.
Good luck!

- Eric
Lurker
Joined: 10 Aug 2010
Posts: 2

Tue Aug 10, 2010 11:04 am quote
I was just searching around and found this thread, post number one and Im asking if there are any updates to this realy interesting subject.
Imhaving probs with my lights on a 66 Super frame with a Sprint veloce engine in it.

heres a link to another site where I have asked other Qs about the engine and frame .

http://www.dfwscooterist.com/forum/viewtopic.php?f=3&t=4113

You guys on here seem very knowlagable and I have many Qs about this project I am doing.
Thanks guys
Member
VBB, sprint engine
Joined: 16 Jan 2010
Posts: 42
Location: Melbourne Australia
Sat Sep 04, 2010 11:15 pm quote
wiring with just three wires from the stator
I love the description from MDmechanic. I was pulling the wiring diagram apart and got some of the way. The description fills in the gaps.

I have an issue with my setup as the stator only has three wires coming from it. I think the engine is an early P series and it is in the frame of a VBB.

If I follow the guidelines in the above posts I should have three circuits. But for me this is impossible as I only have two live wires (- the third is a ground). One wire will be used for the coil, sparkplug circuit, leaving just one for everything else.

Could someone explain how I would adapt the wiring diagrams for the headlights, horn circuit and tail light, pilot and speedo circuit to run in a single circuit?

Also, when I dismantled the bike it had a rectifier wired in. It is a non-battery type bike so is a rectifier necessary? or what purpose does it serve?

Thanks,

HW
Hooked
GS 160 /4
Joined: 01 Mar 2009
Posts: 402
Location: Maine, USA
Sun Sep 05, 2010 6:16 am quote
Hi HW.

I'm afraid I'm no expert on P electrics, or on conversions, but the answers to your question will depend on the exact details of what sort of motor, whether the stator is original or modified, and how the installer wired it all up.

Essentially, you need to start with engine number, whether electric start, electronic ignition, 12v or 6v, etc. (because you never know what someone else did), come up with at least a basic wiring diagram by testing to see what goes to what, and take some pictures, and then someone on this board (not necessarily me) will have enough info to answer your question.

I have looked at a few diagrams, and I must say, I can't answer your question with the info I've got.

- Eric
Member
VBB, sprint engine
Joined: 16 Jan 2010
Posts: 42
Location: Melbourne Australia
Sun Sep 05, 2010 6:47 am quote
I'll get more details on the engine number and how the stator is wired and post them. For the meantime - It is not electric start, not electronic ignition and has some old 12V bulbs in it.

The Stator is not modified - it had three wires coming from it originally.

Regarding the rectifier - would anyone know how this functions in a non-battery bike? I'm wondering if having this in the circuit would allow all the bulbs, brakes and horn to come off the same circuit?

I'll put up some more detail in the next 24 hours.. thanks for the help so far.

HW
Hooked
Joined: 25 Aug 2010
Posts: 401
Location: United Kingdom
Sun Sep 05, 2010 10:50 am quote
Re: wiring with just three wires from the stator
hotwheels wrote:
I love the description from MDmechanic. I was pulling the wiring diagram apart and got some of the way. The description fills in the gaps.

I have an issue with my setup as the stator only has three wires coming from it. I think the engine is an early P series and it is in the frame of a VBB.

If I follow the guidelines in the above posts I should have three circuits. But for me this is impossible as I only have two live wires (- the third is a ground). One wire will be used for the coil, sparkplug circuit, leaving just one for everything else.

Could someone explain how I would adapt the wiring diagrams for the headlights, horn circuit and tail light, pilot and speedo circuit to run in a single circuit?

Also, when I dismantled the bike it had a rectifier wired in. It is a non-battery type bike so is a rectifier necessary? or what purpose does it serve?

Thanks,

HW
More than likely it was a regulator that was fitted not a rectifier. This would allow all circuits to be fed from the one stator supply wire.
Member
VBB, sprint engine
Joined: 16 Jan 2010
Posts: 42
Location: Melbourne Australia
Mon Sep 06, 2010 5:55 am quote
I have a feeling you are right and a regulator was wired in. THe regulators I see have three points - is this simply the live cable going in, joined by earth and the new regulated live cable coming out?

I have a question about adding a kill switch. Where can I get a switch that I can use for all the functions - lights, horn & kill?
Banned
2:6
Joined: 11 Jan 2007
Posts: 7466
Location: San Francisco
Mon Sep 06, 2010 6:59 am quote
Regarding coil output of more than 6volts: Starting in 1974 US models had two yellow wires coming from the stator into the junction box. These were not grounded anywhere and produced 12-17VAC. The rectifier was a single diode that basically tossed the negative half of the output to give you 6VDC out.
Hooked
Joined: 25 Aug 2010
Posts: 401
Location: United Kingdom
Tue Sep 07, 2010 12:31 am quote
oopsclunkthud wrote:
Regarding coil output of more than 6volts: Starting in 1974 US models had two yellow wires coming from the stator into the junction box. These were not grounded anywhere and produced 12-17VAC. The rectifier was a single diode that basically tossed the negative half of the output to give you 6VDC out.
If the stator coils are not grounded with two wires going to the reg/rec then it will be going through a bridge rectifier for full wave DC.
Also rectifing 12V AC through a single diode will not give 6V DC, it will still be 12V albeit half wave.
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