'75 XS no Spark so I want to change the ignition system. Need advice

speeedracer27

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Recently added a 1975 XS with a side hack to my stable. Bike sat for 10 years, in a garage. It's in pretty good shape, no corrosion, altogether pretty clean. I plan on taking it apart, cleaning it up, replacing whatever I need to replace and reassembling. Have decent compression, wiring is in pretty good shape. No rust, and NO SPARK. I went through the usual systems checks. Points look decent. Coils test at 4.3 ohms and 37,000 on the plug caps. All of the connections in the headlight are OK. Switches are OK, still no spark. Been years since I messed with points ignition. Really don't want to waste too much time with it. But I haven't moved to dismantle anything else trying to "find" the probelm. The real question is, do I spend any more time chasing down the gremlin or do I just take everything apart (really want to do that) and order an electronic ignition set-up? If so, what's the best system? (PamcoPete seems to be out of the game). I'm not doing a full restoration but want a clean & reliable ride. If anyone has suggestions or a set-up to sell, please let me know.
 
In my view some work should be done on the existing installation wiring and ignition

a ) Often not to say virtually always the problem is not the Ignition itself ,but rather the wiring
most often the ground .. So You might end up doing the same job with the new fresh bought electronic ignition
Which wont fire either if the connections + wiring is bad.
b ) With an unknown bike I think i would try to start it .. Getting an overview of the status and costs coming
to make decisions moving forward.

I have used Boyer Branden ---2 different on bad Charging bikes and had Bad wiring 1980 s .. I suppose it has worked even if it is sensitive to low voltage
Do you know the mileage ..
Do you have a Voltmeter checking voltage at fex Points
 
Boyer is a very good ignition system. Comes complete with advance, coils and everything needed. You will have to make a new coil mounting bracket. There are cheaper alternatives.
 
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I agree, wiring can be an issue. I have power at the red/white wires and coils. Not sure about anything else at this stage of the game 28,000 miles. Not sure what you're referencing in the 2nd question.
 
I agree, wiring can be an issue. I have power at the red/white wires and coils. Not sure about anything else at this stage of the game 28,000 miles. Not sure what you're referencing in the 2nd question.

In my view 28000 is at the short end distance ... a bit early for splitting the engine if compression is good and no other problems rattle ..smoke and so
With a hand held Voltmeter taking the readings experienced people here could help out finding the Gremlin.
 
Checked the compression. It was 80 and 96. This is after sitting for 10 years. I sprayed some PB blaster to break some stuff lose. Will check valve clearance when I get the ignition figured out. I see that 130 -150 is considered decent compression. I don't mind the mechanical stuff, I just hate cashing down electrical gremlins...
 
Yes, the points need to make good contact and flow current when closed. If you checked the gaps with an oily feeler gauge, you may have contaminated the points faces and you won't get any current flow through them. Strips of business card sprayed with electrical contact cleaner and dragged through the points like a feeler gauge is the usual cleaning routine.
 
After some years in storage, I had no spark on my 650D. It ran perfectly when put away. So I just started some systematic troubleshooting, and found the main culprit to be the kill switch having high resistance.
When troubleshooting, there is a few things to be aware of. It is rarely a full open circuit, but some level of high resistance. Which means one may measure full battery voltage at the coil +terminal if that set of points are open (zero current draw, so no voltage drop even with significant resistance)
The coils have a rather convoluted power supply, with many possible problem areas. Battery to fuse, to ignition lock, to kill switch, before arriving at the coil +terminal. Also, the wiring is pretty small gauge. The same goes for the wiring from coil negative to points, but that is not as bad. What I am trying to say here, is that the entire circuit, from battery + to ground at the points plate needs to have minimal resistance. Just open and clean one connector at a time, and one switch at a time.
Fitting any battery powered electronic ignition, like Boyer/ Pamco/ XS Charge/ Dyna/ Newtronics/ Pazon/ Ignitech will still require wiring in good condition, so these steps need to be taken in any case.
My final solution, after cleaning up connectors and switches, was "the relay mod", which means a dedicated, direct power wire from battery, via a relay, to coil +terminal, reducing any voltage drop significantly. This relay is then controlled by the original power feed to the coils. I used 2.5 sq.mm wire for this supply, probably overkill. This is a cheap fix, as you only need 1 m of wire, 1 relay, 1 fuse holder and some female spade connectors (or a relay socket) The same can of course be achieved with a full rewire, using a MotoGadget M-unit to take care of all switching on a bike, using handlebar switches as control inputs only.
The only commonly available ignition system that does not need power from the battery, is the Vape (Powedynamo) CDI/PMA setup.
 
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But do you have continuity across the points when they are closed ? You have to take the wire off in order to check this.
Not necessarily. If the coils have power, and everything is connected, you can use a voltmeter and measure voltage across the points. Open points should give 12.6V (battery voltage), closed points should read less than 1 V.
Just to be clear, the negative probe on the points plate, positive probe on the wire/connection on the moving point.
(Been a while since last time, wonder if capacitor/condenser needs to be disconnected first, either you measure resistance or voltage)
 
Could the capacitor/condenser be bad from sitting? Is there a step by step on how and what to check throughout the electrical system?
 
Could the capacitor/condenser be bad from sitting? Is there a step by step on how and what to check throughout the electrical system?
Yes, the capacitor could also be bad. But you need to check the entire system, starting with the batrery. Voltage should be 12.6 volts, measured with a digital voltmeter. 12.0V is pretty much a dead battery. Did you read my post (#9)?
It takes maybe one hour to unplug connectors, clean and reconnect, and clean the kill and ignition switch, plus the points. As a quick check, you could run a direct jumper from battery + to coils +, preferably with a 10 A fuse. This will bypass any issues in wiring loom and switches, and you should have a spark if coils, points and the wiring from coils to points are all ok.
 
WHAT . no warning for the gummed up carburetor yet I am surprised
Mr articXS seems to have it ( As others ) ..
The separate wires to ignition has worked as a time saving method finding problems
But it is more common i Believe the Ground - is wrong
The + is simpler to measure at consuming point
if it is a quick start. One is after
I would

Take down the carburetor Bowls from under ( if the tank is inspected cleaned and OK )
If the bowls look acceptable
Flush through some gas so the Float valve operates --- manually operate it.with the hand ( Careful about fire )
( disconnect the fuel line before doing it )
Check the Voltage at Points and coil. about 12.V
Check the ground Wiring from ignition and coils
Take out the plugs give it a little oil in the cylinders
Have the plugs on-against the engine and with the 12 V at points look for spark at plugs kicking.
As mentioned points can need a cleaning but there are also special files for it. and some Carborundum paper can be one way
It needs to be clean at the Points inside not only the contact point itself. false grounding is common . Solvent perhaps and clean up
Capacitors age with time ..Sometimes on fex HiFi they can need a while before starting to do their job if been without power for a longer time
But can also be broken.

The word is that this method has the risk gum up the Carburetors if unlucky .But it is a lot of work do the overhaul.
Which can be avoided to some extent .Summer is Coming and Why not go for it this season ??
Compression test did not appear stellar ..but can be OK it is difficult to test correctly and it has been sitting others can have a better opinion on that
 
OK, my friends. I have been trying to chase down this gremlin and so far I have the following to report: The frame and engine are matching and are original 1975. Although I have been warned about Clymer's inaccuracies, the wiring diagram in my service manual shows that the wiring schematic matches 650D model (1977). All of it looks completely original. All connectors, wiring loom straps, and alike have not been altered and I would say, with confidence, that everything is factory original. I tested the system and all (that I was able to test) looks OK. Coils are at 4.8 Ohms, and 15K to the spark plug ends. I don't know how to test the condenser and also not sure what some of the other components are (attached are pictures. Please fell free to identify and ridicule me for not knowing 45 year-old technology). From what I can tell, there is a useless safety relay and a light indicator doodad under the battery box. I think my rectifier is smoked. No continuity and it looks pretty well corroded. However, this is a charging part and should not affect the spark (correct?). I jumped the coil "hot wires" with a positive lead and got no spark at the grounded spark plug (well almost no spark. There was one or two tiny sparks and then they were gone as well). Took the headlight apart and removed it (for the time being) and reconnected all of the wires to make sure something was not corroded in there. Points look clean and the alternator brushes are withing spec (also charging component). I ordered a new condenser and points kit (off eBay) just to make sure this is not the problem. I'm leaning towards ordering the PMA kit from Mike's https://www.mikesxs.net/xs-charge-xs650-pma-gen-ii-standard-electronic-ignition.html since I'll have to replace the rectifier in any event. I'm not looking to save a few bucks on vintage technology. Would rather do it right the first time... Admittedly, electrical is my least favorite part. Once I have this sorted I will deal with the mechanical part of the bike. I have carb. rebuild kit, tank sealing kit, and other bits and bobs to make her purr. Thank you, everyone, for your knowledge and advice. Keep 'em coming!
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Hi
Unfortunately

I think my rectifier is smoked. No continuity and it looks pretty well corroded. However, this is a charging part and should not affect the spark (correct?).

If you print the type of machine and / or a schematic or link I can study the wiring
I have an 80 and there are fuses for each subsystem . I don't know for your model
But I guess that you have only one fuse --- looks so 650D model (1977).
Each subsystem light / charging / ignition and so on are at the end of them connected to ground minus
And on upside to 12 V
And each subsystem has a Design Resistance ( or impedance )
If that Resistance gets to low via a broken Component ( Rectifier ) more current can run there to ground at the Experience of other subsystems.
So if the rectifier partially or more Short circuit the Voltage feed -- it can reduce the Voltage available for the Ignition
And then it wont fire ..
In fact a charging problem is a very common cause for bike stalling.
Not seen the wiring but one way forward perhaps is disconnect everything except the ignition
Careful...........
( I assume a not running bike ) have 12 V or more at the Points and kick see if spark gets better

I am a Low budget Zero Cost lot of Work rider
I would wait ordering that
https://www.mikesxs.net/xs-charge-xs650-pma-gen-ii-standard-electronic-ignition.html

$ 454 could go down the drain if fex a Gearbox problem is there discovered later.
I would at least drive a couple hundred miles before ordering.


 
Thanks for the feedback.byes, there is only fuse. I replaced it with a modern blade-type. The D is a 1977 mine is supposed to be the B, which is 1975. Slight difference. Rectifier shows an additional ground and a couple of other small changes, but nothing material. I did disconnect the entire electrical system, ran a jumper to the coil and no spark, still. I'm thinking the condenser might be a problem or perhaps the coils gave up the ghost. I have 12.6v at the points and I can get then to spark with a screwdriver. Do you know what the diode is for and also, what is that big silver doodad in my 1st picture?
 
Aha. I though so. He's also not working. If the condenser and points don't resolve the issue. With power going directly to the coils, would you then suspect bad coils or is there anything else that could be tested?
 
Thanks for the feedback.byes, there is only fuse. I replaced it with a modern blade-type. The D is a 1977 mine is supposed to be the B, which is 1975. Slight difference. Rectifier shows an additional ground and a couple of other small changes, but nothing material. I did disconnect the entire electrical system, ran a jumper to the coil and no spark, still. I'm thinking the condenser might be a problem or perhaps the coils gave up the ghost. I have 12.6v at the points and I can get then to spark with a screwdriver. Do you know what the diode is for and also, what is that big silver doodad in my 1st picture?

Within the last month or 2 we had a gentleman at Jersey Shore that had spark at the Points but not at the Spark plug
in his case --Cause was Ground wire from battery to chassis
I Recommend a perfect service for the ground wire from coil and points In fact better than perfect
If possible a jumper ground direct to the battery
Last half year we have had 6 .---8 bikes with poor ground as the main problem.

Diode Looking at the Schematic XS650 B i Have not a Clue Yet why it is there
shall try to figure it out
 
I don't have a battery in the bike. Using a jumper battery and cables. Negative to the frame, positive to the main wire (before I took out the battery box with all the electronics) and to the coils.
 
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