Cables Gauges Switches Hoses
How to purchase, replace, repair, and route cables, gauges, and switches on your bike.
Questions on cables, gauges, switches & hoses remain a lively topic being discussed on most bike forums. It isn't because they are complicated, but there are many unforeseen pitfalls that can cause problems. This page will attempt to answer some questions, give some tips, and try to point you in the proper direction when dealing with these items.
The throttle cables consist of two cables, that are routed from the carbs to the right hand throttle twist grip. One cable is used to pull the butterflies open against a spring tension. This is commonly referred to as the pull cable. The other cable is sometimes wrongly referred to as the push cable, but doesn't actually push, but is attached in such a manner as to pull the butterflies closed. These cables are in constant use when the bike is running and do wear out from use.
The first indication of throttle cable problems is that the engine does not respond to the throttle. A broken pull cable will not allow the bike to rev up, while a broken retraction cable may not exhibit any noticeable symptoms. This is due to the retraction spring on the butterflies providing the necessary force to pull the butterflies close. Some do operate the bike without this cable, thinking that it is redundant, but a smoother action and the safety of knowing that you can pull the throttle closed would be reason enough to keep both cables operating.
Replacing a set of throttle cables can be a half day project even tho it appears to be a very simple swap. The reason is that the clamshell will need to be opened against sometimes stubborn screws, and the carbs will have to be essentially removed to disconnect and reattach the cables. The first step would be to detach from the carbs. If you are not familiar with carb removal, there are posts and directions on how to do this. After the cables are loose from the carbs, attach a sturdy string to the ends at the carbs. By pulling a string thru with the cables, you have a built-in guide as to re-routing the new cables. And proper routing is very important. Having the bike decide to rev up when the bars are turned can lead to some interesting situations you don't want to experience. So, keep the routing original!
When you have the cables loose to the grip, you can unscrew them from the throttle assembly. Pay attention as to which cable is wrapped in what direction before removing the old cables. Then thread the new cables into the assembly and tighten them up. Using the mentioned string, pull the cables back thru to the carbs and re-attach. Make sure you get the correct cable on the proper holder when installing. A easy way is to just twist the throttle at the handlebar. The cable that retracts (shortens), is the pull cable that opens the butterflies.
Final adjustments should allow some "play" in the cables at the carb and handlebar end. You want to feel a slight turn of the twist grip before the carbs begin to come into play. If you don't allow a bit of slack in the cables, you may experience binding and the carbs not fully returning to idle when the throttle is released.
Here is a write up on replacing a pull cable: Pull cable replace
- The cable that drives the tachometer is one of the simplest ones on the bike. It consists of a tightly wrapped spiral of small wires twisted together. The end that enters the tach head has a square profile, while the end entering the tach drive behind the fan has a fitting with a slotted end. The inner cable cannot be removed from the upper end unless it has broken. Due to the fitting on the lower end, the complete inner cable can only be removed from that end.
- There are several issues that can occur with this cable. The most common is probably a squeaking noise, maybe accompanied by the tach needle jumping. This is generally due to lack of lubrication of the inner cable. This lubing is easy to do, and should be performed when the rear drive is serviced, or every year of riding. Simply unscrew the fitting from the tach head and drop 4-5 drops of light machine oil down the center of the cable. Air oil works fine, 3 in 1, or any light oil is good. As the cable is routed downward, the oil should find its way the length of the cable.
- Another issue is when the tach doesn't work, or reads incorrectly. This could be due to a broken cable, a bad tach drive, or a bad head. I currently own a GL that I restored that the tach would read consistently low and somewhat erratic. After many attempts to diagnose the problem by replacing the cable, and tach head, I removed the tach drive from the engine. Looking inside, I could see that the spiral gear on the camshaft that drives the tach cable had sheared its teeth. Interestingly, the inner cable would still turn with the engine running by close contact of the two gears. But you could actually hold the inner cable at the head with your thumb and forefinger. The cause of this failure I think was due to moisture entering the cable and rusting the inner cable to the the outer sheath. When the engine was started or cranked after many years of sitting, the weakest link was the cam gear. It is still non functional as repairing it would entail replacing the complete camshaft.
- If when you remove the coupling from the head and the inner cable does not turn with the engine running, suspect a broken cable first. To remove the cable from the tach drive, a JIS (similar to philips but won't chew the head screw) head screw will have to be removed from the drive barrel of the tach drive. This can be accessed without removing the radiator, fan, shroud, fairing, etc, but it is a very difficult procedure especially if you have never removed one before and don't know what to look for. I did it with a 24" extension, a Philips bit, and a ratchet, but got very lucky that the screw wasn't extremely tight. The screw has to be completely removed for the cable to come out, so just loosening it doesn't help. Replacement of the Philips screw with a Allen head is recommended when you are reassembling as they are much easier to grip and will hold on a wrench.
- Replacing just the inner cable is possible, but you will have to fashion one from a speedometer cable from a auto parts store. I have done this, but unless it is an emergency, replacing the entire cable is best. You will never know why the original broke, and there is probably rust inside the outer sheath. If you decide to replace the entire cable, tie a string to the lower end to provide a route and puller for the new cable. Then pull the old one out, pull the new one in. Insert the end into the tach drive and rotate the inner cable with your fingers while lightly pressing the cable completely in. The slot on the cable end needs to align with the tab inside the drive for the cable to seat. Replace the locking screw, attach to the head, and you are finished.
- The speedometer cable, like the tach cable is simple in design. They are almost the same, except for the drive ends and length. The same advice on lubing is also appropriate for this cable. 4-5 drops of light machine oil every year, and the cable will last a lifetime. Let moisture enter and don't lube it, and problems will develop quickly.
- Perhaps the most difficult part of replacing a speedometer cable is removing the Phillips screw that locks the lower portion into the drive. Not all models use this, but most do. The screw is a oval head/countersunk style that is extremely easy to round out. I have butchered a couple even with a impact screwdriver. What does work is to chuck a impact head onto a air impact and set the impact to just rattle. Hold the wrench as tight as possible in the screw and let the impact vibrations bring it out. If you have stripped the Phillips head, often times using a Dremel with a cutoff wheel will allow you to slot the screw head. The combination of the viberations of the slotting and then driving a flat impact bit into the slot will usually allow for removal.
- The cable simply withdraws from the drive once this screw or retainer is removed. The other end at the head is also just a finger nut over the speedometer head drive. Again, not a bad idea to attach a string to allow the new cable to follow the old path when replacing. The only other trick is to rotate the top end of the cable as you are inserting into the lower drive. This will align the slot and tab and allow the cable to seat.
- I have replaced the inner cable on 4-5 bikes by getting a universal speedometer replacement from a auto parts store. The process isn't difficult, and once done several times only takes 10 minutes to fabricate a new inner cable. The universal cables are long enough to provide 3 inner cables for the CX models. The process starts with measuring the exact length of the old inner cable. Then add about 3/16" to this number. On the first cable from a new package, the squared off end will already be done. Just measure the old length (+3/16), and cut the new cable with a Dremel. Don't use a cutters, pliers, hacksaw, or your pinking shears as you will unravel the cable. Now insert the old cable's drive end into a vise with the fitting flush with the jaws of the vise. Using a good Vise Grips on the old cable and the leverage by prying on the side of the vise, the old cable can be removed. It originally was crimped in place. Now clean out the drive fitting using a drill bit the same size as the new cable and try to insert the new cable 3/16" in the drive end. When you are happy with the fit, clean all surfaces (End of cable and end of drive fitting) with carb cleaner or equivalent. Now keeping the fitting in the vise, but extending out a inch or so, add some solder flux to both parts. Now heat the drive fitting with the new cable inside until solder just flows into the cable and drive end. You don't have to overdo it, a big glob will have to be worked down to allow the cable to be inserted in the outer sheath. Your are done!!!!
- On the second and third cables of a package, you will have to recreate the squared end. The easiest way I have found is to allow solder to flow thru the cable for a inch or two and then place the end horizontally in a vise with just a fraction of the cable above the jaws. A common file will then work the cable to a flat, then rotate the cable and do another side. Grinding wheels are tricky to guage angles and amount taken off, the file works as quickly and is much more accurate.
- This isn't strictly about the cable, but often when the front wheel is removed, the speedo drive slips down. It is important to align the tabs on the drive with the slots in the wheel (and maybe even straighten the tabs a bit) in order for the drive gear to mate with the wheel's rotation. And before you tighten up the axle assembly, make sure the drive is fitting properly in the fork recess, and that the cable is allowed to flow from the drive at a smooth angle. Three things to align at once, but not difficult to do.
- The choke cable on these bikes is a simple pull cable located next to the ignition switch. The 1978 models used a different style that I am not familiar with, so all comments will be directed to the more common type. In operation, this can't get much simpler. A knob on one end of a wire, hooked to a bellcrank on the choke butterfly. Pull the knob and the butterfly closes and provides a richer mixture for the engine to start and warm up. The only adjustments are the clamp on the carb can be moved slightly to insure that the butterfly opens completely when the knob is down, and a tension adjustment nut under the rubber fitting below the knob. This will allow more tension to be applied to the choke cable to prevent the knob from closing on its own.
- Often times this adjustment has been maxed out on these bikes. I have tried a variety of repairs from roughing up the inner slide, filing notches in the slide, and even fabricating a thin strip inserted between the tension fingers and the inner slide. Nothing seemed to work for any length of time. Replacement may be the best solution, after you get tired of a clothes pin, heavy duty paper clip and vise grips hanging out from under the knob.
- The clutch cable is also a simple cable, but performs a vital function that is difficult to do without. Therefore, examine the cable ends carefully and replace the entire cable if you notice frayed or displaced wire strands at either end. The end of cable life is approaching quickly.
- Replacing the clutch cable is straight forward if you remember the routing of it. It is a good idea to tie a pull string on one end to verify the route, and/or take a quick photo. It is easy to think that you will remember how things go, until you have a interruption halfway thru and you don't get back to it for 2 weeks. Remove the clutch lever first, then you can pivot the lever to allow the cable end to be removed from the lever. This also allows for additional slack at the clutch arm. By pulling the cable up and out from the adjustment bracket, you can gain additional slack for removal. A Crescent wrench or Vise Grip on the clutch arm and using it to rotate the arm may also help.
- Installation is the reverse of removal, as they say. Don't forget to lube the pivot bolt in the lever during installation. Make sure that the two lock nuts are positioned above the fixed bracket at the arm and adjust the slack so that there is approximately 1/2 - 3/4" movement of the end of the clutch lever before you start to feel tension to the clutch arm.
- The speedometer head is what registers speed, total miles ridden, and a resettable odometer to show miles since last reset. As such, the head is rather complex in its inner workings. A complete discussion of repair is beyond the scope of this writer and the purpose of this post.
- There are several areas that seem to be a reoccurring question. One is: How do I get inside the case? There are only two options that I am familiar with. One is to uncrimp the chrome band between the halves. You only have to do one side, generally the back is done to minimize visual effects on the bike. This involves using a small screwdriver or other tool to continually go around the crimp until it is open enough to remove the back half. This is much more difficult than what it sounds like, in that the crimp is very tough to pry up and eventually the blood from all your puncture wounds will cover the seam. Cursing has also been tried an it doesn't seem to be of any benefit. It can be done if you are patience enough and the advantage is that the repair is almost unnoticeable when the head is re-installed.
- The second way us to use a Dremel tool with a thin cutting disc to slice thru the band at the bottom of the head. A jeweler's saw or thin hacksaw will also work if you are careful. Once the band is separated, the halves can be opened up and removed. The top half should be able to be rotated in such a manner that the odometer reset knob can pass thru the hole in the case half. You may have to remove the rubber boot first to allow the knob to pass thru. With the top removed, the inner workings are held in the bottom half by two screws on the back. This should allow you to completely remove the inner cluster. When it is time to put the case back together, the easiest way is to drill a small hole close to each end of the cut part of the band, and use a SS twist tie to cinch the bank back.
- The now exposed parts can be serviced. If the unit was working before you opened it up, you may only want to insure the two face holding screws are snug, and oil any of the bearing points. Since this is similar to a clock, I use a clock oiler that contains a special oil. These should be available on-line and have long, almost hypodermic end on a squeeze tube. This allows you to place a micro drop on tiny bearings to avoid oil running everywhere. Also oil the inside of the drive coming into the head. This is a common area for squeaks to develop. Also check that the two magnetic hemispheres do not have grease on them that causes them to bind with each other.
- A real caution__ is to not use a spray type carb cleaner around the inside of these heads. Any contact with the cleaner and the face or mile numbers will cause the numbers to melt off. A Q-tip with cleaner is much safer to remove old grease and oil.
- There has been some discussion as to how to reset the mileage on these speedometers. Also on how to remove the number face. Both of these are addressed in the following links and do not need reviewing here:
Thanks to LRCXed for the fine photos and write up on the topic of reseting mileage and needle removal.
The tach head is constructed similarly to the speedometer unit, with the exception of the mileage numbers. Most tachs in the CX & GL series also incorporate a temperature gauge in the unit. But the opening, lubing and servicing the unit is similar.
Both units register their information by a needle that is connected to a half hemisphere that rotates within another half hemisphere at a angle. The shells are magnetized and as one turns, it drags the other along thru magnetic action. This is a ingenious method of providing a indicating needle approximately 350 degrees of movement, while using a rotating input from the engine. The needle uses a hair spring to return the needle to its stop.
Lubrication is the same as the speedometer unit, with no points of lube for the mileage register. A bouncing tach needle is usually due to lack of lube in the entrance bearing or the inner cable. To address the entrance bearing lube, the tach should be removed from the bike and placed with the cable entrance at a vertical up position. Add 4-5 drops of light machine oil to the outer area of the inner shaft and turn the shaft with a screwdriver to allow the lube to flow downward into the bearing. Leave the head set for a few minutes and re-install.
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