Tach on a 250 Monza?

[JimF]

Could the mechanical drive from a twin be extracted from its bevel cover and installed in a single's cover?

I realize this is no small task, that it would require a competent machinist and some careful preparation...

[Rick]

Eurojamb and Classic Ducati sell everything needed to assemble the tach drive/cover.
Modifying the gearbox cover from a twin to work on a single would be way more trouble than it's worth- the profile is the same around the top and most of the side, but the single unit is shorter. So, after extensive cutting/welding/shaping, the alignment of the camshaft and the tach drive would require line boring through the head, getting the engagement depth right, etc, plus, the twin engine turns 'backwards'- too much work.
Will attach a picture of a single cover on a twin gearbox casting.

tach gearbox covers.jpg

Those tach drive covers are on Ebay fairly regularly, or the assembly can be built from new reproduction parts.
Rick

[Crazygreg]

Don't forget that most tach drives comes without the little extension piece and oil deflector.. mostly lost over times when disassembled, not possible to use the drive without these parts:

[halfpast]

Don't forget that most tach drives comes without the little extension piece and oil deflector.. mostly lost over times when disassembled, not possible to use the drive without these parts:

Good to know, thanks!

[Jordan]

I'd call the centre item an Oldham coupling, because it can compensate for shafts that are not in alignment.