SPEEDO CABLE BROKEN IN SPEEDO DRIVE HOUSING CBR 125 R 05

The Speedo cable has probably broken.

This is usually due to a broken speedo cable. The cable breaks when the lubricant in the speedo cable housing thickens beyond use from age, if the cable housing leaks and rust forms, or the speedometer itself gets gummy and hard to turn with age.

If the cable is broken, ensure free operation of all the parts, and then replace the cable.

Sound a lot like a broken speedometer cable, a fairly common problem.

Take the cable housing off the wheel, and at its other end, and check to see if either end has broken off. Many speedo cables have the ends squished into a square shape, and the shoulders of that squareness are what drives the cable at the wheel end, and drives the speedo mechanism at the other end. Check to see if that squareness has been rubbed round, rather than square.

If this has happened, replacing the cable will fix you up, but the problem will happen again, soon. If it is broken or worn, either the cable is not turning easily in the housing, or the speedo mechanism is too stiff to turn.

If the speedo end is broken, the mechanism is the problem. If the wheel end is broken it can be either cause.

This depends on whether the speedo is a mechanical or an electronic unit.

If it's a mechanical unit, it probably gets it's drive from a cable that runs to a cable drive unit on the axle that is driven by the front wheel. If this is the case, the problem could be in the speedo unit itself, the cable could be broken, or the drive unit could be broken. To find out which, you're going to have to gain access to the cable by either taking the front wheel off or the dash to get the cable loose from the speedo. Pull the cable out of it's housing and inspect it. Look at both ends, they should be "squared off". If not, the cable is broken and you'll need a new one. If the cable does not look broken, lubricate it some wheel bearing grease and reinstall it into the housing. Twist it a bit while pushing it into the housing to make sure it seats in the drive unit. Raise the front end of the bike and spin the wheel. Watch for the cable to turn. If it turns, your drive unit is probably alright and the speedo is where the problem is. Time for a new speedo in most cases.

If the speedo is electronic, this kind of simplifies things but not much. The speedo gets a pulse from a sensor in the transmission. The sensor is located on the transmission on the right side of the bike just behind the chrome shifting mechanism cover on top of the transmission. It is held in by one small bolt or screw. Remove the screw and work the sensor out of it's hole. There should be an o-ring on the sensor, don't lose or break it. Wipe the face of the sensor off with a rag. Sometimes they get a small bit of metal on them and they quit working. Reinstall the sensor. Take the bike for a ride and see if the speedo works now.

If the speedo is electronic and it does not "light up", then you need to trace the circuit that it gets it's power from. To do that, you need a schematic. I'll like to help with that but I do not have a schematic for this particular bike.

I hope this helps. Good Luck and Ride Carefully.

either a broken gear or cable would be my guess.

This depends on whether it is an electronic speedo or a mechanical speedo.
The electric speedo has a sensor near the rear of the engine. Sometimes a very small piece of metal will get stuck on the end of the sensor and the speedo will stop working. Remove the bolt holding the sensor into the engine case and carefully pull the sensor out. Wipe it off and reinstall it. If the speedo still does not work, it's probably something in the speedo itself.

On a mechanical speedo, a cable from the front wheel drives the speedo. The cable or the speedo drive unit may be bad. To check the cable and drive, lift the bike off the ground, disconnect the cable from the rear of the speedo. Turn the front wheel and see if the cable is turning. If it is, it's probably alright. I'd still pull the cable out of it's housing and lubricate it with some grease. If the cable is turning, the cable and drive unit is alright. The speedo may be broken.

it sounds like the clock spring or gears might be broken you could try replacing them prob cheaper to get second hand ones

well you can but it is a bit more difficult than that as you will need allignment tool to replace and also the might be excess tension and you might need a pulling tool also to remove. it is very unusual that the mechanism drops into the gearbox though? well without effecting the performance of gearbox such as whines and creaks?

First: you unscrew the cable housing assembly from the back of the speedomiter housing.

Second: you pull the speedomiter cable from the housing.

If the cable is broken inside the housing you must unscrew the housing from the spedomiter adaptor on the front axle,. at this point you should be able to pull the broken end from the adaptor with a pair of pliersif you can't pull it at this point you will have to pull the front axle and take the adaptor out and try to remove the broken end.

I hope this helps.