I discovered almost by accident (thanks to M Donati in Vevey...) that all Modenas have an Achille's heel that need to be cured to avoid complete destruction of the engine. This is done as a normal "upgrade" campaign by Ferrari, but of course you've got to know... It has to be replaced with a more robust unit, which requires an engine-out job. The thing is called in French "variateur de phase des arbres à came". Which I have no clue how to translate in english. Camshafts phase variator ? ... Whatever, especially if like me you bought your car 2nd-hand, get it checked !