MD600:
should a robbo with 11 hour to next 100 hr check have black treacle oil anyway ?
No, but the oil does tend to darken fairly quickly. But without a picture of said oil its difficult tell what state this particular engines oil was in.
how often is oil changed in a robbo and is it always changed at 100 hrs ?
At my place every 25 hours i.e. on the 100Hr Insp, then a 25 hourly, then at the 50Hr Insp and then again at 25Hrs (75 post 100Hr)
what is the oil consumption of a robbo?
Couldn't really tell you. But in my experience R44 II's like to be on 7 qts (dipstick minimum) and will happily stay there for a good few hours. R44 I's sit happily at around 8 and R22's 5Qts. Not really consumption figures, but They are all slightly different.
Hope that helps a tad!