Harry Bloomfield wrote:
on 11/01/2007, supposed :
I want to sharpen the cutting blade on the petrol mower ( Briggs and
Stratton engine/Lawnflite SP mower ) but how do I lock the engine so
that I can remove the nut that holds the blade in place ?

You should not need to. Isolate the ignition, to make sure it cannot
start - pull the plug cap off. Then use a well fitting ring spanner get
the engine on compression and give the spanner a clout with a mallet.
Be aware that these bolts are usually of a thread which tightens in the
opposite direction to the blades normal rotation so it cannot unscrew
itself in use.

In other words, the nut is loosened in the same direction as the blade
rotates.

It's much better to free the nut by impact than by hauling on the
spanner, but for maximum impact the blade needs to be held against a
really solid stop like a C-clamp over the grass skirt. That also give
you a hand free to keep the spanner from flying off.

If you think the grass skirt couldn't stand it, that mower is not worthy
of your DIY skills.


--
Ian White