Ok further investigation:
according to this site the MC16 uses completely different setup to my PGM, from the diagrams at least. My bad.
So I discounted that, got the bike started and it was running on one for the first 20seconds. A bit of gentle prompting with the throttle got some smoke out the other one with a few crackles and misses then it started right up.
With both of them running I let it idle, which it did without too much bother for a bit, revved it to ~5k and the first cylinder which was running stopped while the other kept going, then it came back after a wee bit!
Revs out cleanly to around 8k rpm and then bogs quick and stalled out at 9. After that I noticed the specks of oil on the ground that was coming out with the exhaust.
So 25:1 is that too rich, is this thing jetted wrong or more likely to be sucking gearbox oil thru and out, fouling the plugs?