Indeed sounds like EMC.
Earthing, shielding, etc.
High V. leads away from rest.
Pazon runs from 7,5 V
Earthing, shielding, etc.
High V. leads away from rest.
Pazon runs from 7,5 V
Misc: Everything Else Comet Pazon, Alton, Mikuni Strange Misfire/Power Loss
- Thread starter revderek
- Start date
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- Tags
- alton misfire pazon power loss
In my experience with Pazon on Comets I have found them EXTREMELY sensitive to EMF interference.
The only way I was able to get reliable Pazon operation was WITHOUT the Alton or its regulator running.
At the time the tri-spark 'low interference' regulator was not on the market and Tri-Spark was also having issues with its own ignition systems just like yours when a Podotronic/Alton regulator was installed
Tri-spark developed a EMF noise filter specifically for use with the Podtronics regulator that is used by Alton and that may fix the issue - bonus is its cheap. It MUST be installed as close as possible to the positive output from the Podtronic regulator to get the best result.
https://www.trispark.com.au/filter-for-electrical-noise-reduction
A more elegant solution is to replace the existing regulator with one designed to have minimal EMF like the new MOSFET unit available from Tri-spark. https://www.trispark.com.au/mosfet-20-amp-voltage-rectifier-regulator
I have NO relationship of any sort with tri-spark
The only way I was able to get reliable Pazon operation was WITHOUT the Alton or its regulator running.
At the time the tri-spark 'low interference' regulator was not on the market and Tri-Spark was also having issues with its own ignition systems just like yours when a Podotronic/Alton regulator was installed
Tri-spark developed a EMF noise filter specifically for use with the Podtronics regulator that is used by Alton and that may fix the issue - bonus is its cheap. It MUST be installed as close as possible to the positive output from the Podtronic regulator to get the best result.
https://www.trispark.com.au/filter-for-electrical-noise-reduction
A more elegant solution is to replace the existing regulator with one designed to have minimal EMF like the new MOSFET unit available from Tri-spark. https://www.trispark.com.au/mosfet-20-amp-voltage-rectifier-regulator
I have NO relationship of any sort with tri-spark
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I agree the voltage under 14DCv is a little low but the charge is going into the battery so I'm OK with that.
The two regulators which I have are different and both give the same output and both seem to function correctly when fed with another source of AC (a simple mains AC transformer). There doesn't seem to be much noise getting through, though I recognise that can cause problems. That the bike runs perfectly simply with the ignition fed from a separate source suggests it would have to be a loop issue if that is where the problem lies. The earth/negative is, indeed, wired to the battery and is good.
However, I'm not happy about the AC ripple so I watched that more carefully. It peaks at just below 0.5ACv at the right engine speed for around 55mph (88kph) which is where the problems start. I played around with putting a diode in the feed circuit to the ignition (which, apart from a common battery connexion is independent of the lighting/charging circuits) and BINGO, the problem disappears and she runs excellently right up through the range.
From this I have installed the diode properly and it clearly stops the negative side of the ripple - if the ripple is actually a spiky waveform then the excursions could be significantly more than the rms measured by the meter.
I think the ripple is induced rather than leakage, so I will experiment with that and it's time to press an oscilloscope into service but for the time being I'll keep the diode installed, maybe make a "proper" filter, and then see where shielding the AC leads and so on gets me.
Regardless, clearly something "went" because the bike had been running fine until then, so I suspect the generator but I can't afford a new one unless I must.
Thanks for the plug-gap suggestion - I'll incorporate that as soon as I'm sure the original issue has been overcome.
Finally, thanks for all the ideas you gave which helped determine where the problem lay and which will surely help others in the future.
The two regulators which I have are different and both give the same output and both seem to function correctly when fed with another source of AC (a simple mains AC transformer). There doesn't seem to be much noise getting through, though I recognise that can cause problems. That the bike runs perfectly simply with the ignition fed from a separate source suggests it would have to be a loop issue if that is where the problem lies. The earth/negative is, indeed, wired to the battery and is good.
However, I'm not happy about the AC ripple so I watched that more carefully. It peaks at just below 0.5ACv at the right engine speed for around 55mph (88kph) which is where the problems start. I played around with putting a diode in the feed circuit to the ignition (which, apart from a common battery connexion is independent of the lighting/charging circuits) and BINGO, the problem disappears and she runs excellently right up through the range.
From this I have installed the diode properly and it clearly stops the negative side of the ripple - if the ripple is actually a spiky waveform then the excursions could be significantly more than the rms measured by the meter.
I think the ripple is induced rather than leakage, so I will experiment with that and it's time to press an oscilloscope into service but for the time being I'll keep the diode installed, maybe make a "proper" filter, and then see where shielding the AC leads and so on gets me.
Regardless, clearly something "went" because the bike had been running fine until then, so I suspect the generator but I can't afford a new one unless I must.
Thanks for the plug-gap suggestion - I'll incorporate that as soon as I'm sure the original issue has been overcome.
Finally, thanks for all the ideas you gave which helped determine where the problem lay and which will surely help others in the future.
Thank you for your excellent description of your testing procedure to diagnose the cause of the problem and what you have done to solve it. I'm sure that this post will definitely be of great interest to many others.
A diode in the ignition feed circuit is an easy way to check for and eliminate any AC ripple problem.
Not as solved as I thought.
I have to add another footnote and invite more ideas!
Adding the diode has clearly made a difference. Today, however, I took it on a more extended run with a pillion passenger and found that as I reached the upper 60s mph (~100 kph) the loss of power/misfire returned.
I think the DC supply is key and plan to install a bridge rectifier and inductor/capacitor filter in place of the diode alone. I may also stabilise this voltage at 10DCv as the Pazon can run happily with a lower supply voltage than that. I shall also look at the voltage across the battery and across the Pazon feed on an oscilloscope. I'm assuming that I'm on the right track but am still open to other ideas.
Since our national speed limit in NZ is 100kph, at least I can keep up with the flow now but snappy fast overtakes may not be a wise manouvre yet.
I have to add another footnote and invite more ideas!
Adding the diode has clearly made a difference. Today, however, I took it on a more extended run with a pillion passenger and found that as I reached the upper 60s mph (~100 kph) the loss of power/misfire returned.
I think the DC supply is key and plan to install a bridge rectifier and inductor/capacitor filter in place of the diode alone. I may also stabilise this voltage at 10DCv as the Pazon can run happily with a lower supply voltage than that. I shall also look at the voltage across the battery and across the Pazon feed on an oscilloscope. I'm assuming that I'm on the right track but am still open to other ideas.
Since our national speed limit in NZ is 100kph, at least I can keep up with the flow now but snappy fast overtakes may not be a wise manouvre yet.
The tri-spark 'filter' appears to be a small toroid ring with a dozen or so turns of wire, encased in a bit of heatshrink. Worth a try??
Absolutely worth it - I've wound a toroid and put capacitors - 0.1microfrads - each side but have yet to encapsulate and install. Thanks for the reference. (Capacitors, of course, to earth not in series.)
If you are looking for "snappy fast overtakes" you might have to consider getting a Vincent with a rear cylinder.
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I think you are fighting symptoms with filters. You said the system worked great for one year. So now there must be a new defect somewhere for your new troubles. Maybe you should disassemble the Alton and look for suspect contacts, broken wires, connections in the wiring of the bike. As the voltage looks a bit low for good battery charging at max. 13 V my bet would be a bad contact/wires in the Alton. I´d do a bench test for checking total outputs with bulb loads plus voltagemeter. Maybe the "ripple" is synchronous to engine vibrations - broken wire effect ??
Vic
Vic
Valid observation. What happened to the installation between June 2020 and September 2021 (see post #1)?