Resurrecting this again. I haven't yet tried to adjust the choke, as I have a query. The issue I have is the immediate startup engine speed, way up around 2500rpm and this is enough to cause a nasty rattle due to the oil pressure not building up quickly enough. Only lasts a second or so but enough to make me wince. If the ambient temperature isn't too low I can immediately blip the throttle and it settles down to around 1500rpm, that I am assuming is the fast idle speed that the above adjustments will alter, and not necessarily the instantaneous 2500rpm that I'm experiencing?. So, will the adjustments above reduce this initial over rev' or only the subsequent fast idle after blipping ?. Maybe something else in the mechanism is sticking ?. There are no other indications of lacking oil pressure. It's the last thing you want to do to a cold motor, rev the nuts off it before oil pressure is up.