Stelvio owner. Decides to fit a pair of O2 Sensor foolers to his bike, a 30 odd thousand Km 2013 model. This promotes massive overfuelling, oil degrades, tappets start to fail, gaps open up, he closes the gaps and keeps riding. Finally brings it to me when it has filled its airbox up with so much oil and fuel that it's dripping out of the throttle body spindles. Bike barely runs. Even though it's got some shity No Name oil filter on it and the crappy O2 sensor foolers ,which I'd advised against, I manage to scab a roller top end for it but on pulling a head I find huge damage to bores and rings are marginal. Also on puting it back together it is obvious that the cam chains are fucked but I try to get it right, pump up the tensioners manually and by spinning the motor on the starter with the plugs out. As soon as it Fire it jumps three teeth on the right cam sprocket and bends the inlets.
No other option now but a full 'Last nut and bolt' strip and rebuild. It'll cost thousands. The engine is close to being scrap.
Case 2.) Owner changes oil and filter in his bike, sets valves etc. starts bike and notices that it is running rough just off idle and spitting back through the TB's.
So he shuts it down and calls his mechanic who advises him to re-check the valves and if they have changed appreciably not to start the bike again but bring it to me. He checks the valves and finds they've all opened up, that's never happened before so he loads it onto a ute and brings it to Bungendore where his mechanic rips the camboxes off and, sure enough, the tappets and cams have just started to fail. Damage is contained and no harm is done. Owner also has full service history and only uses factory parts bought from yours truly so there will be no argument about warranty replacement.
As a bonus it turns out that his bike needs the kit I was sent wrongly first time around for the above mentioned Stelvio and I hadn't sent it back to the importer yet! Bonus.
Less than a day after he rolled it off his trailer and into the shop its repaired, up and running like a champ.
I think there is a lesson to be learnt from this. Well done Ralf Z. Doing the right thing isn't difficult and is a lot cheaper in the long run. Really!