Key to Lubricating the Cable is to Apply Lubrication from End to End

The cables that transmit the delicate operation of the throttle and clutch play a modest but important role, and regular cleaning and lubrication are essential for smooth operation. There is more than one way to replenish the oil, but be careful not to do it half-heartedly as it will only cause dirt to build up in the cable.

The friction of the cable can shift the tempo of your ride.

Kawasaki GPZ400F has two throttle cables, one for pull and one for return. There is an adjuster in the middle part of the cable apart from the handlebar switch part. Instead, there is no adjuster at the end of the cable which is assembled to the throttle drum holder.

Even if you inject cleaner or oil for cleaning or refueling, it will leak from the adjuster part of the middle part, so wrap the packing wrapping tape around it to seal it. You can also use plastic tape.

Electronic throttle control, which replaces the role of the throttle cable with an electrical signal, has become widespread, enabling precise control not possible with an analog throttle cable. At the same time, electronic throttle control has eliminated one maintenance item related to cables.

We operate the throttle as a matter of course when we drive our motorcycles, but there are times when the cable movement is poor and frustrating. One of the most common is friction and poor return when opening the throttle slightly from fully closed. When the engine speed does not drop quickly, and the engine speed is slightly higher than idle, and the throttle is reversed, the engine speed finally drops, it is something bothering.

Apart from refueling, this symptom is often caused by the cable routing and layout from the cable throttle to the carburetor, so care must be taken when performing maintenance that involves attaching and detaching the gasoline tank, steering wheel, and carburetor. Around the area from the head pipe of the frame to the bottom of the tank, parts such as the main harness of the electrical system and the ignition coil are crowded together in the limited space when it comes to a four-cylinder engine, and if the throttle cable is placed without thinking deeply, it may be pushed or bent, resulting in poor movement.

The larger the slot opening, the stronger the return spring on the carburetor side is pulled, and the greater the force to close it, but at small openings, the friction of the cable will defeat it. Therefore, if you feel any discomfort in the throttle movement after the cable connection/disconnection process, you should recheck the cable routing.

The same applies to the clutch cable. The clutch cable itself is thicker and has a stronger spring than the throttle cable, but the weight of the lever changes depending on how it is routed around the handlebar clamp and headlight stay, affecting the subtle half-clutch operation. The combination of electronic throttle control and the hydraulic clutch does not require such care, but there are still a lot of cable-type motorcycles in the world, and many riders are riding with a lot of friction due to poor handling and poor lubrication.

It is important to flush out dirt and rust with a wash before refueling

If your parts cleaner nozzle is thin enough, you can insert it into the gap between the outer and inner cable and spray the cleaner. The cleaner that goes inside the outer tube and flows out from the other side should be black and dirty, so clean the inner cable by stroking it as far as you can and rinse it off until the cleaner is clear.

The cable injector is a useful tool, but depending on the diameter of the outer cable fitting, the rubber seal inner diameter of the injector may not fit. If the two diameters match perfectly and the lubricant nozzle can be inserted without gaps, the lubricant can be fed very efficiently.

If you cut a little end of a plastic bag with a zipper that you can buy at a supermarket or home center, insert the outer cable and wrap the plastic tape around it, you can easily make an oil injection funnel. If you put engine oil or wire oil into this bag and hang it up straight, it will flow in and lubricate the inside by itself.

Throttle and clutch cables, brake cables if you have drum brakes, which are common on scooters, and even speedometer and tachometer cables if they are mechanical, all need proper oiling.

In order to reduce friction and increase service life, today's cables have evolved to use stainless steel double-stranded wire for the inner and Teflon tubing for the inner surface of the outer. However, as the cables continue to be used outdoors, dust and dirt can get into the gaps between the outer and inner cables, and at the same time, rainwater can get into the cables when they are used in the rain or stored. Also, when laying out the cable, it is essential to draw a loose curve as much as possible and avoid small bends, but even so, maintenance is essential as the inner cable rubs against the Teflon tube at curves to create friction.

According to one of the professional mechanics, when they do the 12-month inspection, they clean and lubricate the cables in the process of checking the operation of each part. Although this work is not mandatory, the life of the cable is definitely extended by oiling, and many users are surprised to notice the lightened operability after the inspection, so it seems that oiling has a definite effect.

When lubricating, it is important to clean first, as well as greasing the drive chain and bearings. If new oil is injected when the inside of the cable is dirty, the cable will certainly move better, but the accumulated dirt may spread widely as it is stirred up, or the viscosity may increase and become less nimble as oil is added halfway to the solidified dirt.

There are several ways to clean the cable, such as attaching an injector to the end of the cable and spraying it with a spray type parts cleaner, or attaching a simple funnel crafted from a plastic bag and pouring kerosene or similar into it. Speedometer and tachometer cables that do not have a tycoon on the inner end can also be removed by soaking them in kerosene or the like to dissolve any dirt that has seeped in if they can be pulled out to one side.

However, when cleaning with kerosene, it is important to spray and rinse the inside of the outer cable with parts cleaner thoroughly to remove the kerosene component before applying oil. Otherwise, the oil that has been injected will not be able to settle due to the kerosene remaining inside, and a lubricating film will not be formed, which may lead to premature wear.

Also, if reddish-brown liquid flows out mixed with black dirt when you stroke the inner cable as far as you can while pouring in parts cleaner or kerosene, the cable may be rusting. The cable is usually broken near the tycoon, but even if the cable is not broken, if the internal friction is increased by the rust, the rough feeling during operation may not be improved by injecting oil, so in such a case, you may replace the cable with a new one as a precaution.

Spray oil can be pumped under pressure or low viscosity oil can be aspirated

This suction type does not have as much pressure as a can sprayer, and can work faster than gravity drop. With the syringe and plastic tube I had at hand, I tried to suck the oil out of the bag.

While sucking secondary air from various places, oil flowed out when I pulled the syringe piston. No matter what method is used, the purpose of lubrication can be achieved if the oil is spread in the outer cable.

When the oil flows out slowly over time, the area around the throttle drum of the carburetor becomes dirty, so I blow off the excess oil with an air blow gun. This does not mean that the oil is degreased, but if you do it too much, the oil film will be reduced, so blow moderately.

When restoring the throttle cable, be careful not to increase the friction in the handling, and apply grease after setting the cable tycoon on the throttle drum.

There are special chemicals used for cable lubrication, such as wire oil and wire grease. While general spray oils with high penetrating lubricity can be used, special products for cables have the advantage of maintaining their lubricity even when water and dust adhere to them. There are also products whose ingredients have been adjusted to ensure lubrication of the contact area with the inner cable, even in the case of old cables with bare metal spiral wires inside the outer cable.

Considering the point of metal to metal contact, it is not bad to inject engine oil. However, in that case, the viscosity is low, and it may be better to take the trouble to lightly blow the air after passing the oil into the outer cable and to drain off the excess oil. There is no doubt about the extreme pressure and lubricity of the engine oil, but in the situation where the oil temperature does not rise, the viscosity is inevitably higher than that of the wire oil, and there is a case where a sense of resistance is strongly felt though it is smooth.

No matter what kind of oil you use, it is of utmost importance to spread the oil evenly from one end of the cable to the other. This is even more important if you have been careful to clean it before refueling. When using a cable injector to inject wire oil, don't worry if some of the oil flows back from the entrance side, just spray persistently until the oil starts to flow out from the other side. After spraying, stroke the inner cable and turn the inner cable in the outer cable so that the oil can spread. The advantage of spray oiling is that it is easy and the work can be done in a short time, but it is also slightly worrying because the momentum of the gas pushes through the narrow gaps in the cable.

In this respect, the method of pouring oil in a plastic bag into the cable by the force of gravity, which some experienced mechanics still practice, is time-consuming and time-consuming, but it ensures that the oil is distributed inside the cable. Placing the cable vertically also has the added benefit of allowing excess oil to flow out of the bottom end of the cable.

Another method is to fill the cable with oil from one side and pull it out from the other side with a syringe. This method takes less time than the free fall method that relies on gravity, and the oil will spread more slowly through the cable because the forced discharge force is less than the gas pressure of a spray can. All of these methods have one purpose, to spread the oil inside the cable.

Unless you are a very sensitive rider, you will notice that the throttle and clutch operation will be smoother after this work. As with tire wear and suspension sagging, increased friction loss in the cables is not something that occurs suddenly and is difficult to notice, but remember the feeling of operation immediately after a thorough cleaning and lubrication, and clean and lubricate the cables whenever they become heavy or rough. If you do this, you will be able to achieve both a comfortable feeling of operation and a long life of the cable.