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Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Comet Pazon, Alton, Mikuni Strange Misfire/Power Loss
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<blockquote data-quote="revderek" data-source="post: 149677" data-attributes="member: 1130"><p>I agree the voltage under 14DCv is a little low but the charge is going into the battery so I'm OK with that.</p><p>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.</p><p>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.</p><p>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.</p><p>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.</p><p>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.</p><p>Thanks for the plug-gap suggestion - I'll incorporate that as soon as I'm sure the original issue has been overcome.</p><p>Finally, thanks for all the ideas you gave which helped determine where the problem lay and which will surely help others in the future.</p></blockquote><p></p>
[QUOTE="revderek, post: 149677, member: 1130"] 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. [/QUOTE]
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Tech. Advice: Series 'B' / 'C' 500cc/1000cc Bikes
Comet Pazon, Alton, Mikuni Strange Misfire/Power Loss
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