NY wrote:
I have a Flymo Hover Compact 350 mower which is not cutting as well as
it used to: it tends to leave clumps and sometimes I have to go over the
same patch a couple of times because initially it bends the grass over
rather than cutting it. This is for normal lawn grass with maybe a
week's growth since the last time it was cut.

I've had the blade sharpened. As far as I can tell, the motor is running
at full speed.

The only thing that is unusual about the blade is that it is slightly
kinked: the last few centimetres where the blade is sharpened bend
upwards by a few degrees (ie the tip is slightly further away from the
grass). Should the fact that the blade is not perfectly flat matter,
given that the height of the cut will be determined by the lowest point
of the sharpened part of the blade.

I'm no lawnmower expert, and maybe someone will have a better answer for
you, but I would suggest that the height of the cut will actually be
determined by the lowest point of the sharpened part of the blade that
is moving quickly enough to cut it. This might not include the bits
further in to the centre. Is the upwards bend there by design? If not,
I would just try bending the tips back down again. Carefully, if
they're sharp :-)