1980 Jota - Instrument Removal

J

Jack911

New member
Location
London
I have a tachometer that’s not working so I have to remove it and send for repair.

I have the bottom chrome cover off and the headlight lens out but it’s far from clear to me how to take the tachometer out.

The mount looks quite complicated and I’ve read that getting it back together can be a bit of a nightmare.

Does anyone know if this has been documented, preferably with photos or video?
 
Disconnect the tacho cable, disconnect the electrical connector to the lights in the Instrument, remove the nuts holding the handlebars release the small bolts in the instrument holder pull the tacho out.
You may find the rubber bulb holders in the tacho have bonded themselves to the unit over time so be careful taking them out or leave them for the restorer to sort out.
I would test the unit using a drill spinning the drive cable anti-clockwise before spending money on it.
 
pf1 said:
Disconnect the tacho cable, disconnect the electrical connector to the lights in the Instrument, remove the nuts holding the handlebars release the small bolts in the instrument holder pull the tacho out.
You may find the rubber bulb holders in the tacho have bonded themselves to the unit over time so be careful taking them out or leave them for the restorer to sort out.
I would test the unit using a drill spinning the drive cable anti-clockwise before spending money on it.
Click to expand...

I took the cable out of the tacho and started the engine. The square end inside the cable was spinning as expected. That must mean tacho fault, no?
 
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the cable might be a crap (Venhill) item that connected originaly to the instrument, but only just and has now stopped engaging, do as Paul says and check the instrument with a drill, or even a screwdriver and give it a flick, be sure you turn it the right way, you might damage it if you force the needle up against its stop by turning it the wrong way.
CLEM
 
CLEMTOG said:
the cable might be a crap (Venhill) item that connected originaly to the instrument, but only just and has now stopped engaging, do as Paul says and check the instrument with a drill, or even a screwdriver and give it a flick, be sure you turn it the right way, you might damage it if you force the needle up against its stop by turning it the wrong way.
CLEM
Click to expand...

I wasn’t aware that Venhill were a bit ordinary, what are the best cables?
 
Have a look at the blue bar above, Library. It might be there and printable. I did the 500 twin manual there to work on my Atlas clutch.
 
CLEMTOG said:
the cable might be a crap (Venhill) item that connected originaly to the instrument, but only just and has now stopped engaging, do as Paul says and check the instrument with a drill, or even a screwdriver and give it a flick, be sure you turn it the right way, you might damage it if you force the needle up against its stop by turning it the wrong way.
CLEM
Click to expand...
If it turns out to be the cable, what are the best cables to use rather than Venhill?
 
Paul Marx said:
If you've got the chrome cover off, pull the instrument upwards.
What have you done to the headlight lens?
Paul
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I tried to pull the speedo upwards and it doesn’t move at all.

Is there anything else holding it in?

Someone else said to “remove the nuts holding the handlebars and release the small bolts in the instrument holder” but I’m having trouble locating those.
 
Hi Jack,I was trying to find a photo of the set up but its not where i thought it was anyway here's an earlier post that may help you understand.

J

Thread 'Mounting gauges'

Is there a "trick" to mounting gauges. I have a 1979 Jota and the gauges mount by steel straps tightening onto rubber mounting bands all held in place by 3 screws. Every time I have done it is a very frustrating experience trying to get the gauges straight and hold everything together then fit the screws. I am about to embark on the adventure again and will appreciate any suggestions to make the job as easy as possible.
Thanks in advance
Ian

Steve
 
Jack911 said:
I tried to pull the speedo upwards and it doesn’t move at all.

Is there anything else holding it in?

Someone else said to “remove the nuts holding the handlebars and release the small bolts in the instrument holder” but I’m having trouble locating those.
Click to expand...
Is your setup original?
Use a fine blade to free the instrument from its rubber surround and squirt some silicone in there.
Paul
 
Post a picture of the instrument set up you have on the bike. The clocks sit in a rubber anti-vibration ring and should just pull out especially if you have undone the small bolts holding the metal band that fits around the rubber rings. Either someone has glued it all together or you may have the later type clocks as fitted to a Jota 120.
 
Photos
pf1 said:
Post a picture of the instrument set up you have on the bike. The clocks sit in a rubber anti-vibration ring and should just pull out especially if you have undone the small bolts holding the metal band that fits around the rubber rings. Either someone has glued it all together or you may have the later type clocks as fitted to a Jota 120.
Click to expand...
IMG_8935.png
 
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