Well I went back to it tonight, tried for a bit and got nothing.
unplugged all the connectors for the reg/rec cdi's and a few extra bullet connectors. Stuck them all back in, wound up the idle screw kicked it and way hey started first kick straight up to a cracking 6k rpm din.
Wound down the idle, and it was going as nice as ever although the right pipe (when sitting on it) wasn't really smoking much at all (just pumping air more or less) just like before.
Tried choke off and noticed the cable had come out of the lever, put it back in turned it off and it started to die revved it a bit manually with the throttle and it just petered out.
Had some issues getting it going again, but I think i'm closer to sorting it. I dumped the coolant ... brown mucky water (not the clean i put in) and a thin oil film on top, reeks of fuel...
so no more running it methinks, until i've pulled the barrels inspected and probably purchased a new top end kit for each piston. Sound like a good plan?