Bernhard said:
Although I have never owned a Ducati, I bow to your superior knowledge on the up keep of these engines, however, back when I was a teenager, I enrolled at the Kirby/ Camp racing school at Brands Hatch when they were the only motorcycle racing school in the UK at that time, and got to ride at first, a non- Desmo 250 and then a Desmo 250, so I could tell the difference between the two. The Desmo 250 was streets faster, would rev quicker and higher, so was a much superior bike and I would have loved one at the time, but I just couldn’t afford one, which was a blessing in disguise as they require a strip down around every 2,000 miles to replace the main bearings, ( Remember this was a race designed engine!) the bevel drive bearing collapses, taking the top bevel with it (
Just for the record, its the big end bearing that was a little fragile in the Duc singles and early v-twins, not the main bearings.
They were apparently fine for the 250 and 175 singles, but when stretched to 350 and 450 desmos, could have a fairly short service life - although 2000 miles sounds rather short even then. They were also a roller bearing bigend, and Duc went to some lengths to specify what oil was suitable for them - multigrade 20w/50 apparently was not on the list of suitable oils. The early desmo 750 v-twins were also a little hard on their big end bearing, and again Duc recommended only some specific oils. Later designs employed a more robust bearing all around. Dunno about that race designed bit, Duc singles started out from fairly modest little ohc singles, and the desmo bit was added to some quite later....
But we diverge, slightly, as Aco like to point out !
