tach and speedo internals

[MotoMike]

Has anyone taken their tach and speedo apart to clean the dials? Mine have a white powdery looking residue on the left side of each. I'm guessing it is from the bike sitting somewhere for a long time alowing it to be exposed to some element coming from one direction, probably sunlight. Is this a job better left to a specialist? Looks like the bezel must be delicately pried off.

Found a curious thing. the bulbs in the tach and speedo are 12 volt 3 watt. Thought at first someone had made a mistake, but the parts book shows this to be correct. Wondered what they were up to. Were 6 volt 1.5 watt not available or did they think the 12volt bulbs would be more reliable at half their rated voltage?

Mike

[Jon Pegler]

Most instruments fitted to Ducati singles are not really user repairable.
They are nearly all magnetic clocks that have the bezel rolled on during manefacture.
These need to be replaced with a new rim if they are removed.
They can be very gently prised off by levering all the way round, but are very difficult to refit without looking like they have been damaged.
Many of them are fairly inaccurate, be they Veglia, CEV, Smiths or VDO, so it can sometimes be worth replacing them with another instrument if originality is not a priority.
I've got a few machines fitted with the larger, older, Smiths Chronometric clocks. They are not cheap, but they are fully re-buildable, have a screw on bezel which makes removal easier, and are infinitely adjustable if you know how. You can re-calibrate them for different tyre sizes , or tyre wear if you're so inclined.
Some of the late Spanish built mototrans engines came with a 12 volt generator as standard. Is yours one of those? It may explain the 12 bulbs in the clocks. Or maybe someone just wanted a dim light.

Jon

[MotoMike]

Jon

thanks for your info. Originality is not a huge deal, but I do love the look of the two chromed cans that the gauges fit into and like the look of the clocks themselves. So unless they fit in those can's, I'd probably live with what ever i can come up with.

Not a 12v generator, not a mototrans. regarding the 12 volt 3 watt bulbs, apparently Ducati put them in there as they appear in the 450 parts book supplement.

[DewCatTea-Bob]

" Were 6 volt 1.5 watt not available or did they think the 12volt bulbs would be more reliable at half their rated voltage? "

____ Yep, all my stock (non-R/T) 450's also came with those 12v instrument light-bulbs, and I had always assumed that the reason was cuz they were more likely to not get burnt-out -(rather shook-out) from vibration.
If those older type of bulbs haven't become vibration-proof by theses days, then LED-type bulbs should work better.


Dukaddy-DUKEs,
-Bob

[MotoMike]

...Many of them are fairly inaccurate, be they Veglia, CEV, Smiths or VDO,...Jon

Since I got my tach drive installed and have been using it, I would have to concur. It gets up to about 4500 and seems to be reluctant to register higher despite the obvious faster revs. plus it oscillates when it gets up around 4 k. Oh well, another thing to add to the ever growing list. Good thing I don't wind it out to the stops

[DewCatTea-Bob]

" It gets up to about 4500 and seems to be reluctant to register higher despite the obvious faster revs. plus it oscillates when it gets up around 4 k.

____ I'm thinking that that's vibration-induced, try unbolting it from it's mount and see if it doesn't then behave better.


Hopeful-Cheers,
-Bob

[jbcollier]

I have the original gauges on my bike for display purposes only. The speedo is all over the place after about 50 kph -- cleaned and lubed cable and gauge -- I use a small bicycle computer for a speedo -- accurate within .5 kph. I "calibrated" the tach against a high end test tach: the original reads roughly 10 % high. Not that it matters much, I chicken out once the needle approaches 2K for the second time.

[JasonB]

I have a special pair of pliers to remove bezels and then re roll them using a jig in the lathe, I should probably say that I own a instrument restoration business and I have done a few speedo (veglia) there are straight forward repair and can be calibrated o.k, parts (ike hairsprings) are hard to source and white face Veg tachos, has a, one of a kind huuge hairspring which normally in older tacs the biggest problem, my own was a night mare to even read right....


my 2 cents

Jason B

[MotoMike]

I have a special pair of pliers to remove bezels and then re roll them using a jig in the lathe, I should probably say that I own a instrument restoration business and I have done a few speedo (veglia) there are straight forward repair and can be calibrated o.k, parts (ike hairsprings) are hard to source and white face Veg tachos, has a, one of a kind huuge hairspring which normally in older tacs the biggest problem, my own was a night mare to even read right....


my 2 cents

Jason B

Mine are CEV clocks. I'll PM you.