tach drive housing types

[Rick]

Brian,
The camshaft on the left in your photo is the one I've seen in 175 engines- with the long taper to neck down the shaft. Your cam on the right must be a 200 cam, with the very short taper- the 250 cams I've seen aren't necked down.
There are 2 different 175 cam grinds, the 'fat' lobe and the slower opening lobe:

175 cams.jpg

I always thought the performance grind had the tach drive slot, but then I noticed this cam didn't have the slot:

175 cam no slot.jpg

So, the factory didn't seem to follow any convention. I don't think any of the production 175/200 models came with a tachometer from the factory- it was an option- it might be that the option wasn't offered at first, and the unslotted cams are from earlier bikes.
Rick

[DBDBrian]

That's interesting re the taper on the shafts Rick. Both shafts were in 200 engines, but who knows what has taken place in fifty plus years.
I intended using the slotted one, It's good too know it's the correct one for a 200, also not having the job of altering the other one.
I would think Ducati were still finding there way with the early machines, and modifying things as and when required.
Brian

[halfpast]

Here's one of the 'integrated' drives shown on a Mach 1: http://www.philaphoto.com/imageLibrary/ ... 1589&pos=8

BTW - that website has great photos of many different Duc singles as well as other marques.

[LexH]

The 100/125/160 narrow case models had a 4-bolt bevel cover as distinct from the 3-bolt triangular covers described so far.

As far as I know, the 125 F3 came with a tacho drive fitted to its 4-bolt bevel cover. Sadly I don't have a 125 F3 so I can't post a photo of the tacho drive. But I can say that my 1966 125 Sport does have a slot in the cam end. And so does my 1958 175 Sport. So although neither, as far as I know, came standard with a tacho, it seems both were equipped to take one.

Lex