How to Complexify a Choke Cable
My TR6 had a dual choke cable with solid inner wire. For
reasons not important here, I wanted to operate the choke levers on the
carbs with flexible stranded inner wires. Determined to re-use as
much of the original control cable as possible, I came up with a hybrid
control cable.
I
started by pulling the inner wires out of the original cable and
cutting off one of the two outer cable sheaths right where it emerges
formthe control head, and cutting the other sheath so it would just
make it through the firewall.
![](./IMG_4157a.JPG)
This
is a Bowden cavble splitter. One cable comes in one end, and up
to four cables come out the other end. The little brass shuttle
inside connects all the inner wires. It is designed to split
sthrottle or choke cables for multiple carbs.
![](./IMG_4154a.JPG)
![](IMG_4153a.JPG)
Though
these devices are intended to work with stranded inner wires, there
isn't any good reason they won't work with solid wire, too. You
just can't plan on having a "push" action transmitted through the
splitter because of the way the inner wires are terminate in the
shuttle.
I
soldered a little brass wire end onto the solid wire of the old
control. Similar to the process for stranded wire, I "upset" the
end of the wire so the wire end was mechanically captured before
soldering.
![](./IMG_4161a.JPG)
![](./IMG_4163a.JPG)
![](./IMG_4165a.JPG)
![](./IMG_4166a.JPG)
Then I made a couple of short cables with stranded wires to go to the carbs.
![](./IMG_4252a.JPG)
![](./IMG_4253a.JPG)
![](./IMG_4159a.JPG)
Putting
it all together and installing it, it was quickly obvious that the
return springs on the carbs would easily pull the control back to the
home (unchoked) position since there was no locking mechanism on the
control head. (Locking wasn't necessary with the solid wire
cable, since it can both push and pull, and return springs at the carbs
were not used.)
So what was necessary was some controlled drag on the cable to just balance the spring tension.
To
do this, I modifided the splitter by making a new end cap that was a
little longer and included a set screw that would push on a little
nylon pellet that in turn pressed on teh solid wire from the control
head. Drag could be adjusted with the set screw.
![](./IMG_4226a.JPG)
So here is the thing installed and working.
![](./IMG_4255a.JPG)
In
the end, although I got it to work well, I decided to scrap the design.
It is complex, a minor hassle to set up and adjust, and works no
better than the stock design.