Wastes no time and acts to start machine? (7,2)
I believe the answer is:
presses on
'wastes no time' is the definition.
(to press on with something is to waste no time)
'and acts to start machine?' is the wordplay.
I cannot really see how this works, but
'and' could be 'n' (common abbreviation for 'and') and 'n' is found within the answer.
'acts' could be 'presses' (press is a kind of act) and 'presses' is present in the answer.
A single letter 'o' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
(Another definition for presses on that I've seen is " Continues".)