Rough mower engine

 
I have a rotary petrol mower, powered by a Briggs & Stratton HP470.
Yesterday I
hit a kerb stone and the engine stopped dead.

I retarted it and it sounded really rough and was vibrating. I removed
the
cutter blade and bent it back to level, sharpened and balanced it
(as best I
could).

Upon re-starting it sounds like a bag of spanners! No smoke but really
noisy,
rough and the engine speed is uneven.

Have I wrecked the crankshaft bearings or can ayone suggest what else
it might
be please?




--
Geoff Griffiths

 

The key holding the flywheel in position could be sheared, altering the
ignition timing. Or the flywheel could be damaged. Either case is the usual
result of an engine coming to an abrupt stop.

 Chas Hurst wrote:

A sheared key would cause it to not run.

--
Art

 Geoff Griffiths wrote:

I have no idea what a bag of spanners sounds like but I'd bet you bent
the crankshaft. Take the spark plug out, keep your eye on the blade bolt
and pull the starter rope. If the bolt head appears to wobble then the
crankshaft is bent. Not much you can do about it. I've whacked them
pretty close to strait with a 5lb maul but you will likely never get rid
of the vibration.

--
Art

 
Dang that doesn't sound so good..the bottom end makes that noise you can't
mistake, for the most part.

 ..is the oil clean?