Vespa Speedo Faceplate Replacement
One of the easiest ways to spruce up a faded speedo is to replace the faceplate, lens, gasket and bezel. This is under the assumption that the speedo is in good working order and you simply want to redo the cosmetics. All the parts can be purchased from Speedo King for roughly 65.00 and the quality is fantastic. If your speedo is dead or real jittery that isn't fixed by a new cable, I strongly recommend sending out to Speedo King to have him personally restore it. He is extremely reasonable in price and his work is top notch.
One of the first things you will need to make is a fixture to secure the speedo and at the same time apply pressure when crimping the bezel. I used a 3/4 inch piece of plywood and traced around the lens of the speedo. The goal is to be able to hold the speedo around the lens and have the edge of the bezel rest on the wood. This will allow you to compress it against the gasket and ensure a tight seal.
As a side note, this particular speedo was out of a VMA bluebadge and actually had a blank where the bulb holder would normally be.
The first thing you will need to do is to remove the brass bezel from the speedo without damaging it. I have tried a number of ways and the one that I find the easiest is a small pair of side cutters to cut and roll the edge of the bezel away
Once the edge has been pulled away around the entire unit it should come off relatively easily
Once the old face plate, lens, gasket and bezel is removed, the new top face plate can be installed. On the bottom side of the face plate is a pin that keeps the needle from going past 0 mph. Using a small pin, you can gently hold the needle above while installing the faceplate. It is also a good idea to wear a pair of gloves so that you don't smudge or leave finger prints on the faceplate or lens.
Using a small pin, you can gently hold the needle above while installing the faceplate. If you install it and you don't see the needle it is on the wrong side of the pin. Gently remove the face plate once again and give it another shot.
Next, install a new gasket making sure that their are no twists in it and that it is all the way against the faceplate.
Install the lens and bezel
Turn the speedo upside down install into the jig you made. Put the jig in a vice and make sure it is snug but not so tight that it may damage the plastic lens. Once you feel that it is located where you want it, press down firmly on the speedo to compress the gasket. The bezel should rise slightly above the area where you will fold over the tab.
When folding over the tabs I begin in the middle and work my way out checking periodically to make sure everything is centered correctly.
Once you are done check to make sure everything is centered correctly and be sure to remember to install the gasket in the headset and to not over-tighten the securing screw. This is the number one reason why speedos stop working.