Vespa Choke Cable

The choke cable on a large frame Vespa runs from the choke lever in the center of the frame below the seat to the carburetor on the right side of the engine. The cable is sold as a single item with a typical outer, but has a wire with pre-bent ends as the cable itself. When the small choke lever is pulled out from the frame it simply pulls the cable by about a half inch which provides a richer mixture for starting.

Unfortunately the cable is located inside the frame and the fuel tank will need to be removed. On the Vespa shown in the picture I have a single front seat and a buddy seat on the standard luggage rack. To remove the front seat, use an 11mm wrench to loosen and remove the three bolts into the frame.

The buddy seat is held to the luggage rack by two 10mm nuts on the bottom side. They are a little difficult to see...

...but a look at the underside of the seat will show them on either side. They hold a small grab bar in place which clamps the seat to the rack. Loosen the nut only enough to rotate the clamp so it passes through the slot.

With the rack out of the way you can remove the last three 11mm bolts holding the rack to the frame, and the rear of the fuel tank to the frame.

Before you can pull the tank the fuel lever needs to be turned to the on position so it faces up as shown. Also the rubber grommet around the fuel lever shaft will need to be removed by prying it out.

Start to lift the fuel tank up by lifting at the rear....

As you do the oil sight glass (if fitted) and the fuel lever will move backwards and into the frame.

Once the fuel lever passes through the frame hole the tank can be lifted from the frame. Sometimes it will need a little help and you can peer into the frame area and see if anything like cables or fuel lines are being caught.

Usually the fuel line will not need to be disconnected from the tank or the carb. There should be enough length to it to lift and slightly twist the tank as shown above. If you have nice paint work, you might want to protect the edges of the frame opening with a rag.

Now you'll be able to see the choke cable (shown with a green arrow) and the frame mounted tube and pin clip in which the small choke plunger fits.

To remove the carb end of the choke cable you'll need to remove the right hand side engine cowl and find the carb box mounted on top of the engine. Using a Phillips screwdriver remove the two screws at either end. Once these are free the top can be removed although it can sometimes need a little effort.

Using a flathead screwdriver, remove the air filter element by removing the two screws. The rear screw is a little weird looking so remember it always goes in the rear hole.

Now you can see where the wire choke cable attaches to the carb. Using a hook of some sort or a flathead screwdriver, unhook the cable and push it out through the hole in the carb box.

Since the carb end is released you can now pull the choke lever beyond the frame and disconnect it from the wire.

Remove the old choke cable and feed it through the hole in the frame. Fit the new choke cable through the frame hole and make sure the end with a loop in it is outside the frame. Push the end of the choke outer cable securely into the end of the frame tube.

Make sure it is fully in the tube or the next step will be very difficult. There is just enough length on the wire to allow you to connect the choke cable.

You'll see the end of the wire poking out of the choke tube on the outside of the frame. The trick is to grab it with some needlenose pliers and....

..thread the wire through the end of choke lever. You can see that one side of the choke lever cut outs is longer than the other (the one on top in this image). Be sure the wire is threaded as shown above to make sure it doesn't come undone in the tube.

With the other end of the cable hanging out through the frame, push the choke lever back into the frame tube. Thread the choke cable through the carb box, and hook it on to the carb hook. Test to make sure the carb hook is all the way released when the choke lever is pushed all the way in, and out when out. If all is well, replace the filter and the carb top.

The final step is to re-fit the rubber grommet around the fuel lever so it doesn't rattle around when driving.

www.scooterhelp.com
Read more...

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.

www.scooterhelp.com

Read more...

Clutch Cable Replacement

This section shows a quick step by step of replacing a clutch inner cable on a large frame Vespa. To find out where the clutch cable is located at the motor end of the bike, have a friend pull the lever while you watch under the motor to see what moves.

As you can see on this oily example, the clutch cable has been fraying at the pinch point and will soon snap....probably on a rainy night miles from anywhere.

The first step is to remove the existing nipple by using an 8mm wrench on the nipple body and a 7mm wrench on the pinch bolt. Once slackened it can be pulled off the cable, or just cut the cable if it is stubborn and wont come off.

The image above shows the cut cable and the following parts: Red arrow: clutch arm, Blue arrow: adjuster lock nut, Green arrow: threaded adjuster.

To remove the rest of the inner cable, go to the clutch lever and remove the pivot screw while holding the nut below from turning. Some older bikes use a flathead slotted nut on the underside.

With the pivot bolt gone you can remove the lever but be sure to note where the small washers are located so that they can be put back in the same manner. Once the lever is free simply pull on it to remove the inner cable and then disconnect the cable from the lever.

Take the new inner cable and thread it in to the outer housing after a quick lubrication with oil. Be careful not to push the cable outer end back in to the headset. A flashlight is very helpful here. Once threaded push it all the way until you see it poke out at the motor end.

Fit the lever, a little grease, and the washers, and then pull on the motor end until the lever goes back in to position. Fit the pivot bolt and securing nut.

At the motor end make sure the new cable inner goes through the adjuster and the actuating arm. Back out the threaded adjuster so that it is in the middle of its range...meaning you could tighten it or loosen it equal amounts. The image above shows that clutch arm a rest and it is spring loaded.

What is very important to understand is that the clutch arm doesn't actually engage the clutch until further in its travel. Push the arm with your finger towards the front of the bike. You'll feel some resistance and then a very definite stop. This is the green arrow area above. This stop point is where the arm makes contact with the clutch and if you were able to push much harder (in the red arrow area) you'd start to disengage the clutch. Many people have emailed me making the mistake that the initial travel is where the clutch arm is disengaging the clutch.

Slip on the nipple and pull on the cable to make sure the lever at the headset is completely disengaged. Then push the clutch arm forward until the red arrowed point discussed before and tighten down the nipple. I find a very useful tool for this is a set of Vise Grips. You can clamp them just behind the nipple so your hands are free to tighten the nipple with the 8mm and 7mm wrenches without the arm moving back in to the green arrow area.

The final step is to go up to the lever and give it a pull. It should move about an 1/8 of an inch before the arm is in the red arrow zone which you'll feel as the clutch will become harder to pull. If you are in this area then you are good to go. If not you can loosen the clutch adjuster locknut, and either loosen or tighten the adjuster. Once finished tighten the locknut so it doesn't move in the future.

When you take the bike for a test drive, it should be easy to shift and not creep when in gear. To test this change in to 1st gear on flat ground with the clutch fully pulled in. If the bike tries to creep forwards you'll need to back the adjuster out more. If the lever can't hit the grip when fully pulled or if the motor RPM can climb not in rleation to the road speed, loosen the adjuster.

www.scooterhelp.com
Read more...