Looking at the back of the standard motorcycle speedometer unit, there are generally just a few screws back there. You may have even taken the initiative to unscrew them to discover – nothing happened! That speedometer is still sealed solid as a rock. There must be a trick or secret to opening a motorcycle speedometer.
The bottom-line or “trick” is that motorcycle speedometers generally were not and are not meant to be opened. They are pressed and sealed together at the factory very carefully with really no intent of ever being opened again. Can they be opened? Sure. Do people open them and fix them? All the time.
Do you see the chrome bezel or rim around the bottom? That is what is holding the whole thing together and the key to opening a motorcycle speedometer.
The trick is to very carefully bend it up from the rest of the motorcycle speedometer housing – just enough to slip it off. You need to work your way around the speedometer bending it up just a little bit at a time. Expect the whole process to take 6-10 minutes. If you do it in less than that, you rushed and you are not going to be happy with the final result.
Let me emphasize that point again. This is a very slow, very carefully done process. Why am I emphasizing this so much? Because this post is about opening a motorcycle speedometer, but ultimately you are going to have to slip that chrome bezel back on and close this thing back up.
The less you bend the bezel out to get it off the speedometer, the less you will have to bend it back to get things sealed back up. The key is bending it out only enough to get it off – no more. If you can do that, when you put it back together, it will look like it had never been opened.
What is the best tool for this job? The best I have found is a small tack remover.
The reason I like this over a screwdriver is the bend in the tip. It allows you to apply a little leverage again the rest of the speedometer housing while bending the bezel up and away. A screwdriver will work but is likely to slip during the process, potentially nicking the edge of the chrome.
One more word of wisdom/warning. If the housing is plastic, be careful as you lever up the bezel. It is possible to apply enough force to crack the plastic speedometer housing and then you will be up a creek without a paddle.
I am going to save a detailed discussion on the insides of the motorcycle speedometer for another post. As you can see, I already hit 500+ words just on opening a motorcycle speedometer. In terms of closing things back up.
Grab a ball-peen or baby hammer, wrap the tip in a small cloth, and simply tap the edge of the bezel back in place. Carefully work your way around until it is solidly back in place. There is no need to hit it very hard.
Also, there is no need to use a silicone sealant when resealing the speedometer – the interior needs to breathe. If you seal it too tight and there is a differential in temperature or moisture between the inside and outside of the speedometer, it will fog up like the dickens (and you will be reopening it again before you know it).
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