Gear/ throttle Cable Replacement

This section shows a quick step by step of replacing cables on an older type (pre P-series) scooter. The first step is to remove the headlight unit with two small screws located at about 4 and 8 o'clock when looking at the headlight. The unit can then be hinged out from the bottom and lifted to release a top pin from the headset. The bulb holder can be disconnected by undoing the two metal clasps that attach it to the headlight.

Remove the speedometer by undoing the center of three bolts when looking at the bottom of the headset. The speedo drive and speedo bulb will also have to be disconnected as you pull the speedometer clear. Once this is done you should see something similar to the picture below.

This sections shows how to replace the inner and outer cables for the gear selector box/ throttle slide assuming that the cables are ready for the trash.

I find it is easiest to simply remove the gear end of the twist grip to get the ends of the cables out at the headset end. Using a 10mm socket, remove the central bolt.

Once the pulley is removed, save the spring washer and locating washer that remain on the twist grip end for the rebuild. Move the cables so that the little "top hat" ends to the outer cable disengage from their supports as shown above. Pull the cable inner out of the outer with a pair of pliers. Once it is out you can clip the head of the outer cable to get rid of the crimped metal end as this could get caught as you pull it through the frame.

If you are just removing the inner cable then replace the top hat over the cable outer end, lubricate the new control cable inner with oil, and then thread the new inner in to the existing outer cable all the way until you see it at the selector box end.

If you are also replacing the outer cable you can clip the head of the outer cable to get rid of the crimped metal end as this could get caught as you pull it through the frame as shown in the next few shots.

Clean the end of the old cable outer and wrap in a spiral motion with a piece of electrical tape. This type of tape works well because you can stretch it to make it really tight. Take the new cable outer and place it face to face with the old and continue the wrap around it for about 3 inches. Repeat the process in the other direction (from the new to the old). Once this is secure it should look like the picture above.

At this point a helper is really handy. One person holds the cable at the headset straight up in the air. At the other end you pull the cable slowly through the frame as person number 2 feeds it in. It should slide right through and poke out the proper hole near the engine. The red arrow above shows the old cable outer and the green is the new cable outer. Carefully unwrap the tape from the cables and move on to the next step of threading the inner cable.

Thread both inner cables with the cable top hats in place and set the hats in the support in the headset. Then carefully fit the end nipples in to the pulley in the same direction as they were removed.

Refit the dished washer and then the locating washer, and make sure the small hole in the pulley engages with the peg on the locating washer.

Refit the pulley and tighten the 10mm nut. Place the twist grip in the neutral position and then move down to the selector box end of the cables.

I've switched the model of the bike in the photos but the idea is the same. At the bottom end thread the cable inner around the selector wheel, through the nipple at the end, and then pull it tight. When you pull it make sure the twist grip doesn't move from the neutral position, and be sure the bike is also in neutral at the motor end. Make sure the cable outer is weal seated in the adjuster and that the threaded adjuster is about 1/2 way out so you can adjust it in either direction if needed.

Using a 7mm wrench for the nipple bolt and an 8mm wrench to stop the nipple from turning, tighten the nipple down. It is helpful to have a helper still pulling on the cable to keep it tight. Do the same thing for the other cable and then wiggle the twist grip without actually engaging gears. There should be about an 1/8" of movement. If there is too much movement, equally back out both the adjusters at the selector box. If there is too little, turn them both in enough to get the wiggle.

Note: An alternative to this method to replacing outer cables is to get an extra long control cable from a bicycle dealer (the type used on tandem bikes). Thread it through the new outer cable first so that the nipple is tight against the outer cable end. Then thread the inner in to the old outer cable still in the bike. This will get you the same result as taping the two outers together as shown above. From here, go to the selector box end and place a gear nipple on the inner cable. Now you can pull the old cable outer and the new cable outer will replace it. Once the new cable is in position, remove the nipple and the tandem inner.