<-=- Club Bevel Heaven -=->

In 1982 I bought a new 900 S2. While riding along the putty road north of Sydney I ran over a patch of loose stones at about 90km/hr as I was approaching a corner.
All of a sudden my engine burst open and all the oil dumped under my rear tyre throwing me down the road. After recovering from my injuries I took the engine to Gowanlocks and after spending $800 (a small fortune in 1982) they rebuilt everything into a secondhand casing plus added a much needed kick start.

The mechanic told me that that it wasn't that uncommon for Ducati motors to sustain damage in this way (BMWs too) and a stone striking a hot motor in the right spot can do some serious damage.
He suggested I get an aftermarket bellypan for it which I did. Later the mille appeared with the same style bellypan, I wonder if Ducati knew something.

I now have an MHR and although I think it looks cool without the lower fairing but I dare not remove it for fear of a repeat occurence.
Here's some pics of the old engine case:

Unless the stone ended up in a carby,possible without a filter just hitting outside after being flicked up sounds like BS to me.Who at Gowys said that.

I don't remember who did the job at Gowanlochs but I remember being very pleased with their service. The mechanic did say he had seen this type of thing before and commented how the bike design made it more susceptible.
I do remember hearing a loud crack as I ran over a patch of stones and then the rear tyre sliding all over the place.
I thought my back tyre had blown and reefed on the front brake but it wasn't enough to prevent me going wide off the bitumen on the corner and down in the gravel. When I stood the bike up oil was still pouring out of a large crack in the front of the motor. The piece in the picture above was still attached but removed during repairs.
The arrow in the picture below indicates a rough area where the crack was opened the widest so appears to be the point of impact. It is also the only part of the front of the motor where there's no protective fins and at a point in the casing where there is no internal support. Sounds plausible to me.

There was some cluey blokes at Gowys then,Arthur for one.Not to meanion Ian.Were they at the old shop then.Long skinny place near Strathfeild.

Yes, I haven't lived in Sydney for 30 years but I remember it being a very small shop where you drive down a driveway to go round the back.
It wasn't far from Frasers where I bought the bike.

Looking at the damage I would surmise it had suffered an impact to that area before you rode it that day unless the
"stones" you encountered were the size of grapefruit. The front of the cases are relatively unsupported in that area but bolted together it would take a very hefty whack to break them open like that.