Moto Guzzi 4 Valve Engines Flat Tappet Fiasco

It is now common knowledge that all 4 valves engines (Griso, 1200 Sport, Stelvio, Norge) will be affected at some point. The Moto Guzzi air cooled 4 valve engine (1151 cm³) is a great powerful engine – the best Guzzi built so far. Unfortunately is has a serious design flaw but it can be fixed with a roller kit conversion. Every owner should invest in this before it is too late.
Roller tappets and camshafts were introduced by the middle of 2012. Engine numbers for the changeover point are listed as:
Griso - motor number A813524, build date 12 April 2012
Stelvio - motor number AC12596, build date 12 March 2012
Norge - motor number AA12214, build date 18 April 2012

More info (written by Pete Roper, Moto Moda) can be found on the "Griso Ghetto" forum
(https://www.grisoghetto.com/t5879-the....
"The earliest 8V motors were made using chilled cast iron flat tappets, these were in 2007 through to early 2009. It quickly became apparent that there was a problem as the tappets started to fail. At this point, from memory around the end of 2008 or the beginning of 2009 the factory did issue an actual recall but not to fit roller tappets as these hadn't been manufactured yet. The first attempted fix was to replace the chilled cast iron tappets with forged steel ones with a 'Diamond like carbon', (DLC) coating on them. This was supposed to be 'The Fix' and as with all recalls was supposed to be publicised by both factory and dealers and, to their credit, most owners were so notified and in my experience it has been very rare to find a cast iron tappeted bike in circulation after the recall.
Firstly it was stated that failures were a rare and unlikely event. They aren't. The attrition rate is 100%. There would be no pre-emptive replacements, the tappets had to fail before a claim would be accepted and the claim for a roller conversion kit was dependent on the owner having a full service history completed not just on distance but also on time, (So if you only did 5,000 km a year you were still expected to get a full 10,000 km service performed annually and recorded in your log book.). No service history? No kit! The inspection for damage had to be performed by an authorised dealer or service agent and provision of the kit was entirely discretionary. The owner was responsible for the labour component of both the inspection and, if the claim was successful, the installation of the kit."