Modern Vespa

I currently own a secondhand Vespa S125. Odometer has stopped working at 79,999.9 km and refuses to go onto the next km, despite having ridden a few hundred km since then. Previously there was the same issue - it stopped at 69,999.9 km but began to work again I think after a week or so.

Other details that may be useful for diagnosis:

* Speedometer is working. However, when odometer stops working at 79,999.9 km and 69,999.9 km, I notice that the speedometer needle trembles/shivers/shakes slightly when I am on the move. Normally it moves in a smooth and constant fashion.
* All other warning lights on dashboard except for low fuel and signals do not work. Signal dashboard light is temperamental - sometimes it works, sometimes it doesn't. Right now the signal dashboard light has for some reason stopped working again after I needed to have the ignition switchboard replaced (to fix a problem with the headlight).

Apart from a complete change of the dashboard, are there other steps that I can first try in hope of making the odometer move again? Workshop recommends changing the dashboard but I'd like to explore other options first prior to that.

I don't have much experience nor tools with taking apart the bike, but any information will be much appreciated. Thank you![/img]

Do these models have a mechanical speedo drive? If so, I'd be replacing the worm gear at the wheel end, cleaning and regreasing.

It could be something sticking on the 10,000 mile digit wheel (im calling it that because i dont know the proper name for it). There are mechanical cogs inside the digit wheel that make it turn, maybe one of these is a bit stiff.

Another thought is that youve got the full load of every digit wheel needing to turn because its going over to 80,000. maybe it needs a bit of manual encouragement to push it over.

Both of these would need the speedo taken apart to some extent.

Have you checked the fuses?

It's a mechanical drive, and I'm surprised you made it that far before failure.

I had to replace them on my Piaggio Fly and Vespa GTS at about 20K miles. If the needle is trembling/jumping, it likely the worm gear on the front wheel is shot. If the needle is totally dead and the odo is not working, the cable is broken and needs to be replaced.

Check your owners manual for the 80k service instructions.