On Tue, 17 Jan 2012 10:29:01 +0000 (GMT), Dave Plowman (News) wrote:

I guess that would still work for petrol engines today but
possibly
not on a diesel.

It would need to be a small engine.

Not sure the size, as in cc, makes that much difference it's the
compression ratio. 9:1 (ish) for a petrol, 20:1 (ish) for a diesel.

If I forget to operate the decompression lever on my single cylinder
diesel genset and try to pull start it it's like yanking a rope
attached to a boulder, it doesn't move once the slack has been taken
up. The single cylinder 4 stroke petrol mower is a doodle.

--
Cheers
Dave.