Unusual crankcases

[Smoggy]

Does anyone know which model these crankcases are from ?

Unknown ducati single.jpg

They are for sale on eBay - https://www.ebay.co.uk/itm/235345712876 The seller thinks that they are from a " later electric start 250"

I have only found mention online of Forza 350s having an electric start, the position of which would explain the missing fins on the front of the right hand crankcase, no mention of electric start 250s. There is a photo of a 350 Forza engine, credited to Phil Aynsley, on Paul Ritter's Wordpress blog, there isn't a filler on the left hand case as in the cases for sale.

forzaelectric.jpg

Dave

[Duccout]

I would guess that the cases are from the end of Mototrans production and that they were using up existing stocks of crankcases, or possibly the last Stradas and Forzas used the same cases to unify production.

Jon may be able to shed more light.

Cheers,

Colin

[Jon Pegler]

Those cases carry a number from a 250 Strada from about 1979/80.
The Strada was never fitted with an electric start, but as Colin says, used the same crankcases as the electric start Forza 350.
Looking at the photos on the e-bay ad it is possible to see the cast in lug inside the front of the clutch and alternator housing to accommodate the electric start idler shaft. This varied from the earlier Forza cases which had a welded in aluminium block.
The later, post 1980 Forza cases had cast in lugs above the gearbox to affix the rear mounted starter.
The oil filler opening was usually threaded on the RH case on most of the late Mototrans cases as the front mounted starter motor precluded a LH filler, but was often threaded on both sides and sometimes just the LH case as the Italian cases. Once the front mounted starter was abandoned, the existing Strada, Forza and Vento models could use the LH filler position. The cases continued to have the front fins shaved however, even though this was not required.

Jon

[Smoggy]

Mystery solved, thanks for your help.

Regards,
Dave