[Flip]

I completely echo the thoughts of Utopia and Darren that the 4v motors are both more complicated and therefore more expensive to keep sweet along with the single sider requiring some unique tools, although on a plus side you don't have to worry about wheel alignment when adjusting the chain.

The blue S4R in Worthing is just down the road from me and I'd be happy to take a look if you wanted- although wouldn't want you parting with money on my say alone.

Before making the trip down yourself you could ask him if he'd be prepared to run it down to Alf's motorcycles for Alf to take a look over it (at your cost obviously). Alf's looked after their own 888 and 748 race bikes along with many others and has always got some kind of Ducati motor stripped down in his private workshop out the back of the main dealership.