Woodruff Key Found In Sump

Looks like it’s from the crank?

 

The url is at the top of his screenshot (https://www.bike-parts-ducati.com/)

Isn't the flywheel outside the crankcase?

 

Does the engine run correctly? If so I would leave well alone... keep it as a spare

(It could have been there since birth)

 

You have a bit of a conundrum. Is it an orphan dropped at some time and replaced? Or, is it a component that is missing? When you consider the purpose of a woodruff key, to provide a secure and non-slip connection between a rotating component and a shaft, then the decision to ignore or investigate is for you to decide. Ignore - may be fine or may be costly. Investigate - will be costly but will give peace of mind.

 

I agree with Chris above, my first thought was it could well have been ‘lost’ and a new one replaced it but if it was mine I’d have to know else every time I was riding it it’s all I’d be thinking about.
Doesn’t look like you would have to split the cases as they are on the outer part of the shaft but ive never worked on one of these so someone more knowledgeable would know.

 

I would believe that if that key had slipped from position that at least it would show signs of damage unless whatever it was holding in position moved out of it’s way for it to deposit itself into the sump cleanly.

Last engine that I had the Woodruff moved from destroyed itself, on the M25.

 

if its been running ok then surely its a bit someone (apprentice) dropped in and couldn't remove, they are essential and take a huge amount of load for something so small

is there any scoring or marking on it??

 

What motor is this from?
I thought both keys are from outside the crankcase?

 

Woodruff keys are for timing. If the key becomes damaged its because the tightening fastener for the component has slackened allowing it to move on the shaft.

 

The witness marks on the woodruff key suggest that it has been ‘run’ at some time, but when installed there is no path for them to migrate from their installed position, so can only come out if the area is disassembled (eg the gear is removed from the shaft).
Do you have the invoice for the rebuild and if so was there a charge for a new woodruff key, which might suggest the one you found was ‘lost’ during disassembly, or even assembly, and was simply replaced with new.
Might be possible to check if the woodruff keys are present with limited disassembly, remove parts to expose end face of the gear(s), and check the locating slot in the gear for alignment and presence of the woodruff key(s).

 

I don't think any are inside the crankcases, they all live on shafts outside.

 

Yes, I agree, however, the key that's been found looks like a Flywheel one to me.

There is a hole for the Oil to drain into the main body of the crankcase right at the bottom of the outer 'Oil wet' chamber behind the flywheel and starter gears.
If the key had been dislodged on removal or fitting of the flywheel it could disappear down that hole into the crankcase.
On my 999 somebody had fitted the flywheel etc incorrectly and a washer had broken up into pieces.
Three of the parts below had gone through the hole and came out when I removed the small casting at the bottom of the sump:

 

This is a 1098 engine, but most Ducati crankcases are very similar.



This clearly shows there are two holes, with raised lips around them, that are large enough for the key to pass through.

I have to say I couldn't ride the bike again without checking to see if the flywheel has a key in it.

I suspect somebody working on the engine lost it through the hole and replaced it rather than try everything to get it out.