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tach drive housing types
Posted: Tue Dec 08, 2015 11:38 pm
by 450jupiter
Hi, I have seen three different tach drive housing covers. A cover that is totally smooth, a cover with Ducati in raised letters and a cover with Ducati in engraved letters. Does anyone know when these were specifically used? My application is a '69 450 Ducati scrambler and I have an engraved cover which I hope is correct for this model because it was not originally on the bike. Thanks, Erik
Re: tach drive housing types
Posted: Wed Dec 09, 2015 1:18 am
by JimF
I too am anxious to hear what was stock on the bike, but regardless most people would not know what was stock so unless it makes a difference to you no one will likely fault you for it.
Keep in mind that tack drives are a little hard to come by, so I am glad you have one even if it's not 'correct' for your model.
Jim
Re: tach drive housing types
Posted: Wed Dec 09, 2015 2:37 am
by Jordan
A good source of info is from photographs in magazines, in the period the bike was new.
Re: tach drive housing types
Posted: Wed Dec 09, 2015 4:24 am
by 450jupiter
I have the one that is all smooth on there right now but found one with the engraved DUCATI which I think is correct for a '69. Thanks for the advice about magazines. This 69 or 70 magazine review I posted on a 2015 scrambler forum last year
http://www.beamimaging.com/The_Big_Duke2.pdf (2.4MB link) shows the '69 450 Jupiter with DUCATI on the cover but a little hard to tell if engraved or raised letters. Notice the decal on the air cleaner. Never have seen one of those before. Wonder what it said.
Re: tach drive housing types
Posted: Thu Dec 10, 2015 5:32 pm
by Ventodue
Hi Erik,
This is most likely the type that your bike would have had from new. This is for a CEV rev counter. Note that the cable exits at the top and the 'Ducati' is engraved.
Tach drive 1.jpg
However, by 1970 (if not before) there was also this type. Still CEV, cable exit still at the top, but with the 'Ducati' now raised:
Tach drive 1a.jpg
Now for another type ...

. This dates from 1970/71, possibly before. The cable now exits
below. The 'Ducati' is raised. And note the screw underneath. This was for an optional oil drain. (I have a photo of one of Bruno Spaggiari's race engines with just such an oil line fitted to this type of drive).
Tach drive 2.jpg
And here's a further variation. The 'Ducati' is now engraved and the oil drain screw has disappeared.
Tach drive 2a.jpg
And finally in late 1972 we get this type. Smiths rev counter, no 'Ducati', no oil drain screw (and no leaks, either ...

):
Tach drive 3.jpg
It's all mighty confusing ...
Ciao
Craig
Re: tach drive housing types
Posted: Thu Dec 10, 2015 8:33 pm
by Eldert
and there is the smooth cover like the one on the right

try to stay away from the alu CEV angle drive . they have a habit of blowing the endcap out
one of the shafts will fall out and the coupling will damage the bevelshaft .
Eldert
Re: tach drive housing types
Posted: Fri Dec 11, 2015 2:23 pm
by 450jupiter
Thanks a lot for the input. My bike is a '69 and from the very early advertisements including the magazine article from the Feb '70 CycleSport magazine (link in discussion above), my bike should have something like the tach drive cover and drive Eldert posted above left. Cable exits low. See attachment from a '69 brochure. Also in '69, the new 450 Desmo is shown with a smooth cover. I wonder if that is what they used for the Desmo. Maybe someone with a 450 Mark IIID Desmo can check their bike for the cover. Thanks again for all the great inputs. Erik
Re: tach drive housing types
Posted: Fri Dec 11, 2015 3:29 pm
by Eldert
Hi Erik
the bottom picture is a sandcast racing cilinderhead . not a production 450 item
the tach drive cover is sandcast to .
Eldert
Re: tach drive housing types
Posted: Fri Dec 11, 2015 4:20 pm
by Ventodue
Eldert wrote:and there is the smooth cover like the one on the right
Thanks Eldert - hadn't seen that type before ...
Eldert wrote:try to stay away from the alu CEV angle drive. They have a habit of blowing the endcap out, one of the shafts will fall out and the coupling will damage the bevelshaft.
Do you know, is that why someone has pasted that red or orange 'I-don't-know-what' on the two drives that I posted photos of?
Ciao
Craig
Re: tach drive housing types
Posted: Fri Dec 11, 2015 4:30 pm
by Ventodue
450jupiter wrote:My bike is a '69 and from the very early advertisements including the magazine article from the Feb '70 CycleSport magazine (link in discussion above), my bike should have something like the tach drive cover and drive Eldert posted above left. Cable exits low.
Good pick up, Erik! I'm going to change my earlier advice - I think you're right. In Massimo Clarke's
Scrambler, Desmo e Mark 3, he reproduces a publicity shot of the 1969 US market 450 SCR and that too has the cable exiting LOW.
Ciao
Craig