Hi
Apologies in advance for the long post. The TL;DR is a well running bike has started cutting out while riding after an "upgrade" I made, which has lead to book reading and confusion.
The bike is a 1976 based customized XS650. Engine rebuilt and bored out to 750. Hugh's PMA kit. Pamco Pete with blue box external e-advance ( this was the upgrade ). Batteryless with Lucas capacitor. Kick only. New simple wiring loom. Basically a new bike.
I made a few decisions early on for the above setup. When I made them I knew little about how a charging and ignition systems works, but just bought parts that looked like upgrades for the barn find XS I had bought. The bike ran for 1200 miles without a hitch after rebuild.
Then I was looking at Pete's site and saw the blue box external auto advance, another upgrade. Bought it and put it on the bike because anything electronic has to be better than something mechanical : ) No problems for a few rides, then the engine cut out leading to a long walk home. Then again. From cold, the bike starts first ( maybe third or fourth ) kick and runs like a champ, right up until it dies and won't start again. I'm 90% confident this is not a fuelling issue as I had the carbs/jets ultrasonic cleaned, there's fuel in the bowls and fuelling has been fine over the previous 1200 miles.
I never learn anything until the bike goes wrong, so set about teaching myself a few things about charging/ignition and my particular setup. Got a multi-meter and learned about testing.
First thing I learned is that Pete ( and other sites selling capacitors/battery eliminators ) for XS650s say not to use his e-advance unit with a capacitor. Lesson learned there. The overall design for the charging/ignition system is flawed as soon as I introduced the blue box e-advance. Is that the only issue ?
Second thing is I have almost no load on the circuit ( only a rear running light ) and with repeated testing I'm seeing 14.9 volts at ( low) idle. 15.2 volts at low revs. More at mid throttle. So I think I've found the cause of my engine cutting out, as I'm assuming those voltages cause problems for the electronic ignition and e-advance. That would appear to be enough ( from reading ) to cook a battery, so presuming Pete's ignition isn't going to stand up to that either. Adding load ( a headlight ) brings the voltage down at the ignition to 13.5 at low throttle.
The questions relate to what I do about it ?
Decision: The PMA is staying in place, so any other changes need to revolve around that decision.
Question: With the reg/rec putting out 15.2 volts and above with minimum load ( it came with Hugh's PMA kit ) I'm assuming it's bad and needs replacing. It tests out OK, but on a running bike it shouldn't be putting out more than 14.5volts. That's it's job. Is that a fair assumption ?
Decision: New 3 phase reg/rectifier goes on. Which leads to.....
Question: If I can't run my current setup with a capacitor, I thought I'd throw on a 4 cell li-ion Antigravity battery. Except I'm reading ( on the Electrex site ) that you can't run a li-ion with a reg/rec as they damage/cause fires/general levels of bad. Is this really a problem ? Antigravity themselves sell reg/recs on their site ( https://www.antigravitybatteries-uk.co.uk/lithium-friendly-voltage-regulator-rectifiers-bike.html ) The one they sell looks very similar to the one I got with Hugh's kit. Are there specific reg/recs for li-ion batteries ? Is "mosfet" the key here ?
Decision: I need to test my electronic ignition setup to see to determine whether I've done something terminal to it by pushing 15.2 +volts at it and it needs replacing ( probably with a Boyer given Pete's recent announcement ).I know a little more now, but not enough to prove to myself whether it's good/bad.
So minimum changes look like new reg/rec to get that low load voltage down and swap out the cap for a battery. If the ignition is toast, then the whole lot comes out from the PMA up.
Apologies in advance for the long post. The TL;DR is a well running bike has started cutting out while riding after an "upgrade" I made, which has lead to book reading and confusion.
The bike is a 1976 based customized XS650. Engine rebuilt and bored out to 750. Hugh's PMA kit. Pamco Pete with blue box external e-advance ( this was the upgrade ). Batteryless with Lucas capacitor. Kick only. New simple wiring loom. Basically a new bike.
I made a few decisions early on for the above setup. When I made them I knew little about how a charging and ignition systems works, but just bought parts that looked like upgrades for the barn find XS I had bought. The bike ran for 1200 miles without a hitch after rebuild.
Then I was looking at Pete's site and saw the blue box external auto advance, another upgrade. Bought it and put it on the bike because anything electronic has to be better than something mechanical : ) No problems for a few rides, then the engine cut out leading to a long walk home. Then again. From cold, the bike starts first ( maybe third or fourth ) kick and runs like a champ, right up until it dies and won't start again. I'm 90% confident this is not a fuelling issue as I had the carbs/jets ultrasonic cleaned, there's fuel in the bowls and fuelling has been fine over the previous 1200 miles.
I never learn anything until the bike goes wrong, so set about teaching myself a few things about charging/ignition and my particular setup. Got a multi-meter and learned about testing.
First thing I learned is that Pete ( and other sites selling capacitors/battery eliminators ) for XS650s say not to use his e-advance unit with a capacitor. Lesson learned there. The overall design for the charging/ignition system is flawed as soon as I introduced the blue box e-advance. Is that the only issue ?
Second thing is I have almost no load on the circuit ( only a rear running light ) and with repeated testing I'm seeing 14.9 volts at ( low) idle. 15.2 volts at low revs. More at mid throttle. So I think I've found the cause of my engine cutting out, as I'm assuming those voltages cause problems for the electronic ignition and e-advance. That would appear to be enough ( from reading ) to cook a battery, so presuming Pete's ignition isn't going to stand up to that either. Adding load ( a headlight ) brings the voltage down at the ignition to 13.5 at low throttle.
The questions relate to what I do about it ?
Decision: The PMA is staying in place, so any other changes need to revolve around that decision.
Question: With the reg/rec putting out 15.2 volts and above with minimum load ( it came with Hugh's PMA kit ) I'm assuming it's bad and needs replacing. It tests out OK, but on a running bike it shouldn't be putting out more than 14.5volts. That's it's job. Is that a fair assumption ?
Decision: New 3 phase reg/rectifier goes on. Which leads to.....
Question: If I can't run my current setup with a capacitor, I thought I'd throw on a 4 cell li-ion Antigravity battery. Except I'm reading ( on the Electrex site ) that you can't run a li-ion with a reg/rec as they damage/cause fires/general levels of bad. Is this really a problem ? Antigravity themselves sell reg/recs on their site ( https://www.antigravitybatteries-uk.co.uk/lithium-friendly-voltage-regulator-rectifiers-bike.html ) The one they sell looks very similar to the one I got with Hugh's kit. Are there specific reg/recs for li-ion batteries ? Is "mosfet" the key here ?
Decision: I need to test my electronic ignition setup to see to determine whether I've done something terminal to it by pushing 15.2 +volts at it and it needs replacing ( probably with a Boyer given Pete's recent announcement ).I know a little more now, but not enough to prove to myself whether it's good/bad.
So minimum changes look like new reg/rec to get that low load voltage down and swap out the cap for a battery. If the ignition is toast, then the whole lot comes out from the PMA up.
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