Broken Ducati Valve Spring!

[V90]

The bike's not 12 months old and has done 6.5k miles and one valve spring is broken. Saw it today while doing the valve clearance check.

[BaggaZee]

Is there no noticeable effect of this? What I mean is, would you have noticed if you hadn't been servicing it and what damage could it cause?

[V90]

In theory there is no need for a closer spring if the closer clearance is zero but for my engine the closing clearance is 0.00/0.05 with the service limit of 0.00/0.20. That top limit is a lot and if the engine had that clearance the effect may be difficult starting and rough idle. The valve would be relying on cylinder pressure on compression stroke to close it completely and at cranking speed especially some of the pressure would be lost. It’s a bit like inflating a tubeless tyre; you need a good blast of air from a compressor to force the tyre beads onto the rim quickly and if you used a foot pump you would lose so much air you can’t do it. At a higher engine speed I don’t think it would be noticeable, as the compression pressure would rise a lot faster than at idle.
I couldn’t check the clearance on that valve without the valve on its seat so I don’t know what the clearances were but engine started ok although idle and just off idle wasn't good which I thought was throttle body balance. The other 3 valves had a closer clearance of 0.05 so that’s the top limit for build and I’m leaving them there but perhaps check again in 6k miles.
The only damage I’m concerned about is where is the bit that broke off? If it went through a gear mesh or got into a ball bearing I guess it would do some damage.
I’ve ordered a new spring with the other service bits and the JHP guy at Coventry only had 4 springs in stock so hopefully it’s a rare one. I’m currently making 2 tools to do the job. The first one is needed to extract the rocker spindle and the other one is needed to hold the spring on the rocker ‘wound up’ as the rocker is inserted. Ducati want about £30 for that and hopefully I will only use it once.
I’m hoping I can fit the rocker with the cam in place or that’s another tool needed to remove a special nut.
I could have done without this and I’ve also got an intermittent problem with the immobiliser as the engine block light sometimes stays on when I switch on ignition
My impression of Ducati reliability is……………