Great that you got it sorted. It is so impressive the way that you go about steady fault finding and testing hypotheses.
Thank you, I’ll have a read of them. As it happens, after spending most of yesterday with the multimeter and oscilloscope on it the fault lies within the after market NLM CDI unit that’s been fitted. The trigger processing part of the pcb has failed. Sadly it’s not serviceable being a completely potted unit. As all other components are working just fine ie stator, pick ups, coils abd HT leads/caps, I’m now investigating if it can be replaced with an ignitech unit.
Sachse do one - see here https://www.elektronik-sachse.de/shopsystem-3/en/digital-ignition-zdg-3-23-for-morini-350.html
Yeah, I’ve seen that one, thank you. However, that’s €400 plus another €180 for the coils, so about €600 all in delivered. The stator exciter, the pick ups, the coils, HT leads and plug caps are all in good working order so I’m trying to keep all of them and just replace the CDI unit, hoping it will come in around 1/2 of the complete Sachse electronic set up. If it weren’t for the fact he has an electronic tachometer which requires a feed from the CDI I could fit a couple of combined coil/CDI units which are designed for Piaggio group scooters and which cost less than €100 for the pair. Depending what ignitech say I still might have to go that way.
Yeah... that is a bugger although the article I posted reckons the tacho trigger comes from (just) one coil. Is it possible to implement summat similar with the Piaggio kit?
And the fact the knowledge is given so freely. Which was, back in the day, the original ideal of the internet - openness and free information sharing without corporate or government control.
All too often these days people join forums with the intention of generating income, whether they are qualified to do so or not
I haven’t had chance to work out how the Tacho works yet. I don’t know if the tacho output from the CDI is an increasing voltage with increasing revs (once the engine’s running) which this drives the needle further round the dial or whether it’s an increasing pulse/per minute from the pick ups. . I’m guessing it’s an increasing voltage. I’m assuming that as the engine spins faster the AC exciter coil on the stator increases its output. Its about 50V ac when the engine is kicked over but 120V ac when the flywheel is spun over with an electric drill. It’s a single output wire from the CDI to the tacho so the CDI must be converting the ac to dc and passing a variable voltage to the tacho which must be earthed to the frame through its mountings. If I have to go down the route of the scooter combined cdi/coil units perhaps I could rig something up that feeds off the increasing AC voltage off the stator. I’ll take a look next week, just out of curiosity.
