As promised :)
Disclaimer: This worked for us, it may not for you. I won't be held responsible for any damage to your bike. If you aren't comfortable with this, don't do it. If you are, you do so at your own risk. Also, PLEASE, do not use this method for a brake or throttle cable!!
On May 21st, 05, we decided to do a little maintenance to Dita, since she was starting so poorly.
After pulling her tank, air cleaner, and carbs off to clean, we also discovered that the choke cable was seized. Ahh crap. Thinking that we might be able to free it up with a little WD-40, we didn't worry too much.
By the next day when it still wouldn't free up, we started to worry. Having called the dealer -just in case- and found out that the choke cable was a $43 and change part, we decided that we would fabricate it ourselves. After all, how different is this from the derailleur cable on a mountain bike? ( A little, but not significantly. :) )
We went to Revolution Cycle, here in Edmonton, where they were very helpful, and gave us a great deal on the parts. They also tried to help us free up the cable... with less success.
It ripped in half when they put it in a vise and tugged.
Oh well, we'd planned on needing the new parts anyway.
What we got there was (including full retail on the parts - our total fix cost us $8, but this was a little more than half of what it would have cost if we'd had to pay full price for everything, still $14 vs $43 for 10mins worth of work sure does seem a good savings.):
3ft of sheathing (approx. $3.00)
1 derailleur cable ( this one had the round end cut off it, ideally, this would be the best end to use on the choke lever side ( i.e. the non-carb side)) (approx. $3.00)
1 elbow (approx. $4.00)
1 bolt with a hole in the collar, and matching nut. This is most commonly used on a mountain bike brake caliper where the brake cable connects to the caliper. (approx. $2.00)
We reused 3 parts from the old cable. The black threaded elbow in the picture above, the end that it screws into, and the spring that goes at the carb end.
The idea was to use the derailleur cable to replace the choke cable. Of course, to buy the -exact- type of cable, with the proper ends on it, was nearly impossible. That's ok,.. I had an idea. :) This is where the bolt and nut come in.
The first half is very easy. Take your derailleur cable, preferrably with the round end left intact, and cut the other end off. This will leave you with a ~6ft cable with one end with a round ball on it. (Don't cut this cable down til I tell you to, even if it's a bit of a pain to work with! :) ) Now,... (since your throttle lever is likely apart at this time, since you had to remove the old one) thread the round end into the choke lever, where the old one was.
easy, eh?
now, take the threaded elbow from the old cable and feed it onto the line, and fasten it in place where it used to go, only on the new cable.
Next, cut the "nut" that the elbow above used to thread into from the old cable, and remove the cable sheathing from inside it with a punch.
Thread it onto the derailleur cable, and screw it right to the top of the elbow threads. Now thread your sheathing onto the cable. In order for the sheathing to sit inside the nut, you may need to strip a little bit of the plastic from the sheathing. Not too much though.
From here, thread your cable, inside its sheathing, through to the carb in the same manner that the original cable was fed. Of course being careful that it won't hook on anything it shouldn't, and not sit on anything that will get hot.
At this point,.. the cable and its sheathing may be a bit of a pain, because it's so loose. Don't worry, we'll take up that slack right away.
On the front of the carb, the same place that you removed the cable, and with the same routing, we're going to connect our new cable.
Now place the elbow onto the end of the sheathing, with the big end sliding over the sheathing. This will take up the slack and help to provide the tension we need to make this all work. Now thread the cable through the second (horizontal) split collar on the 2nd carb, and slide the spring onto the cable, but let it sit without being connected to the second collar (where you will connect the bolt to) for the moment.
Now what you want to do, is to put the bolt into the space where the end of the old cable used to live. The way this will work the best is if you put the bolt in on the front side of the carb, i.e. where the carb points toward the radiator. Hint: If you turn the bolt so the hole in the collar points down, to the same direction as the slot in the cable holder here, it will make the next step easier.
Next, you want to thread your cable into this hole in the bolt, don't worry, it's supposed to be a tight fit. Once you've done this, put the nut on and tighten it. Now you can also fit the spring into its final resting position.
Hmmm,.. this cable isn't nearly tight enough to operate the choke. This is what we found as well, so a little kludge was to go out and pick up a 1/16" aluminum sleeve to make this tighter. (These cost us about $2 at Candaian tire - any hardware store should carry them, probably even walmart, etc.)
On the right hand side of the bolt ( furthest from where the cable is feeding) thread this onto the cable, all the way to where the bolt is. With it as close as you can get it to where the bolt is mounted, thread the end of the cable through the other side of the aluminum sleeve to make a loop (ours is a little bigger here than it should be, but it doesn't interfere with anything, so we're not too worried. Of course, learning from our pitfalls, I'm sure yours will be neater. :)
Keeping that cable nice and tight, and as close to the carb connection as possible,... squish the crap out of it, to make sure that cable can't go anywhere anymore. Once this is done, you can cut the excess cable off, carefully. I suppose that you could forgo the loop, but it seemed a good idea at the time, since if it ever let go, I didn't have to worry about any pieces falling off into anywhere they shouldn't be.
Once this is done, make sure to take up any slack at the other end, using the threaded elbow and nut, the same way that you would do with the original cable. ( Not too much though, we don't want to have the choke in an always partially on position.)
Now,.. one last step that we did was to tape up the elbows and nut a little with racer tape, to help prevent water from getting in again. (Since the amount of rust found inside the original sheathing seemed to indicate that that was the source of the problem in the first place.
Alright! That's it! A little wordy perhaps, but hopefully helpful. Please do let me know if you do try this, and how it goes for you. I tried to be as clear as possible, but would love to know about any problems you might encounter.
Topic: How-to: Make a choke cable for a B4 (Warning 8 low-res imgs) (Read 3624 times)