On Apr 2, 8:03*pm, Colin Stamp wrote:
Hi all,

Ebay recently provided me with an old Hayter Harrier 56 lawnmower,
sporting what Hayter call a "Blade Brake Clutch". I've never had a
petrol mower before, so I don't really know what to expect, but the
first cut didn't go as well as I'd hoped. The engine kept bogging down
whilst mowing but it was particularly bad whilst engaging the cutter.
Even If I tipped it up so the blade was well clear of the grass,
engaging the cutter would momentarily load the engine to a near stall.

At the weekend, it wouldn't start at-all and seemed not to have too much
compression. I started to take the head off today and discovered that
all the head bolts were finger tight except one, which was missing.
Coincidentally enough, the head gasket looks like it's been blowing for
some time...

Inside, it doesn't look too bad. The bore and valves all look OK to my
never-seen-inside-a-mower-engine-before eyes. Hopefully a new gasket and
bolt should see the engine back to reasonable performance, but a quick
test of the blade brake and clutch makes me think that was part of the
problem too.

I can easily spin the engine by hand with the cutter drive lever at
either end of its travel, but there's a patch in the middle where the
engine gets very difficult to turn. Obviously, the blade brake is still
on when the clutch starts to engage. It seems wrong - I would have
thought that the brake would release first and then the clutch would
engage. Then again, perhaps it's normal, to prevent a free-wheeling
blade, and a working engine should easily overcome the momentary load.

What does the jury think? Should I fiddle with it?

Cheers,

Colin.

The way you think makes far more sense, and sounds like the problem on
that side.

The bolt arrangement says to me there's something serious the last
person didnt bother to fix - but perhaps its just the brake mechanism,
you never know.

I trust you'll sharpen up the blade, mowers run much better when its
kept sharp, and drink less.


NT