It's a blown head gasket isn't it?
Long story that I'll try to make as brief as I can.
888 started to puff out white 'smoke' shortly after being started up. Smoke was puffing out of the vertical header to collector joint, so tightened it up and it stopped.
Next time it started, did it again - although not from the exhaust joint this time, generally from round the oil breather. Looked like there was evidence of oil misting and hose around the oil breather joint a bit perished/split so cut 10cm off and rejoined.
Got a paddock stand (at last) and then noticed that the oil level was half way between the full mark and the top of the sight glass - oil hadn't been touched since the bike was serviced when I bought it 3000 miles ago. I've been checking it as best I can but usually by way of it reading a bit low when on the stand - so it's been overfilled.
Changed the oil filter and changed the oil for 3.5 litres of 15/50 fully synthetic and the smoking all but stopped (but haven't had chance to take it for a good run). I had a theory that it was breathing in oil fumes from an overpressurised crankcase hence the 'smoke' and the reason that the zorsts look a bit sooty.
Left it ticking over yesterday to warm up and the exhausts started to look a bit 'smokey' after a few minutes (actually more like the condensation you get an a cold day than smoke) but at least it's only coming out of the exhausts now - not from the general header/oil breather area.
However, as it got up to near 80 degrees and the thermostat opened, it started to gush coolant from the expansion tank. Now I did overfill the expansion tank by a mere smidgeroo, but it seems to me that the coolant system is being over-pressurised.
I think I've got (or had) two problems that both give similar results.
1) Overfilled oil from previous service leading to puffing out of the oil breather and putting a fine mist over everything nearby due to the slightly perished hose - in turn creating smoke as it burned off (a tiny little bit of oil creates a lot of smoke and there wasn't that much smoke to start with - just wispy stuff that lasted a few minutes)
2) Potentially a blown head gasket - unless anybody has an easier explanation