In the time honoured fashion of TM thread drift, I had issues with my +8 rev counter some years back, and as best I can remember, I ran a flexible non insulated and braided auxiliary earth strap from my rear mounted battery earthing point through the Mog, adding a link as it passed by the gearbox to provide an auxiliary engine earthing point and carrying on to end up at the bolt fixing the coil to the inner wind..... Unfortunately it did not resolve my taco issue but hopefully provided a bit of belt and braces in terms of possible chassis earthing as the old thing ages... (-:
Having a rear mounted battery, I tend to connect my CTEK at the alternator using the crocodile clips, neg clip to the alternator`s fan belt connection point, and the positive to the alternators output connections. It has been working that way for decades without issues, though that might not work for some... I defer to anything Richard V6 might care to add to the method of CTEK attachment..
BTW, I sent my rev counter off to be repaired at the time, it too has been working well for quite a few years now... (-:
