Throttle cable for scooter and moped
The throttle cable is a flexible Bowden cable (cable) which establishes a mechanical connection from the handle to the carburettor. The throttle cable leads to the slider of the carburettor, which is lifted accordingly by the turn of the throttle grip in the carburettor and thus increases the supply of the petrol-air mixture. The throttle cable leads from the throttle grip to the throttle valve of the carburettor, via which the mixture quantity is regulated.
construction of the throttle cableThrottle cables are available in various lengths and designs. Some scooters require a model-specific throttle cable. This can have a special mounting for fastening, the cable can be divided or have a fixed angle piece at the end of the cable. Other scooters can be fitted with a universal throttle cable. In principle, however, each throttle cable has the same structure.
The outer shell consists of a metal-reinforced inner spiral. This spiral is covered with a plastic cover (mostly PVC). Usually it is black, but also available in other colours. The inside of the throttle cable forms the so-called "soul". This pull rope consists of twisted steel strands, rarely also of a weight-optimised aluminium alloy. On some models, the pull rope is additionally coated with plastic, which is intended to achieve corrosion resistance and better gliding properties. It is not uncommon for the throttle cable to be provided with a sealing elastomer sheath. The PTFE throttle cable offers a maintenance-free alternative. Its interior is made of Teflon.
Which throttle cable is fitted to my scooter?Which throttle cable is installed on the vehicle is sometimes quite easy to see. If this is not the case, you should find the right throttle cable directly by searching for a model of your own vehicle. Although the sheath is setting-optimized and the cable is only slightly longer, you should consider determining the length by measuring it yourself as a last resort.
Check, maintain and change the throttle cableIf the throttle grip is difficult to turn, this may be due to a problem with the throttle cable. In this case you should first check the entire throttle cable for damage. If the outer sheath is torn at one point or otherwise visibly damaged, water easily penetrates into the interior and the pull cable corrodes. The pull rope may also have been damaged. There is no way around an exchange. This also applies if you find kinks in the Bowden cable.
A Bowden cable should be maintained regularly. The effort is not too great. But the choice of the right lubricant is crucial. Simple chain oil and similar products resinify easily and soon hinder the pull more than they help. WD-40 on the other hand, is extremely well suited thanks to its excellent creep properties. You have to be careful with this agent with the PTFE throttle cable, which is not oiled anyway. The well-known multispray causes the Teflon rope to swell and can destroy it.
The interior can be cleaned with brake cleaner. The cable is completely degreased and the dirt is rinsed out. Afterwards the rope has to be well greased again. It is recommended to use an oiler such as Buzzetti.
The correct installation of a Bowden cable is not exactly a science, but some points should be noted. In order to ensure smooth operation and proper functioning, the cable should be laid in the largest possible bends and as directly as possible from throttle to carburettor. It should not be hindered by other Bowden cables. Narrow bends create higher actuating forces and the throttle cable wears out more easily. The throttle cable must not be pinched at any point and should not rub against other components. If the engine speed changes when the handlebars are turned, the throttle cable is stretched involuntarily somewhere. If the Bowden cable is installed correctly, it can be fixed along the frame with some clamps. Everything should still be loose and the clamps should not be completely tightened.