The bike has a full wave regulator + rectifier combined and the OE replacement part is expensive but Elextrex do a suitable cheaper aftermarket part. It arrived this morning so I fitted it tonight. The first thing you notice is the replacement is twice the size of the original and won’t fit the original location but it does have connectors that fit straight to the loom. Thankfully the bike has an aftermarket rear shock with no external reservoir so there is a space where that should go I could mount the reg/rect in.
As I removed the old unit, I found a hidden metal clip which had half sawn through the leads to it. Gah! This would explain the cut outs, the single dead phase and the other electrical gremlins. If I’d found that on Saturday night I could have repaired it and used the bike on Sunday plus saved the cost of a new unit assuming its undamaged from the shorts. Ah well.
After fitting the new unit, its noticeably easier to start, so far so good. The road test revealed a horrible misfire after higher rpms just like it did in the field. Much faffing with spark plugs ensued but that wasn’t the problem. Dismantling the CDI/ECU connections, applying copious WD40 and reassembling did fix it though.
So its ready to go playing in mud and I have an unusually strong urge to use it. Roll on the weekend (assuming I can find anyone to play with).