Mixture control ("choke") cable

[nutmegct]

On my '57 Traveller 948, I pull the choke knob fully out, and see a slight indentation in the top of the cable, at the point where it comes out of the dash panel when the cable is fully pulled.

The handbook says "pull out and turn anticlockwise to lock".

Turning the knob anticlockwise (or clockwise) doesn't lock the cable into position; it just rotates right back.

What is the purpose of that indentation? Assuming it's the catch for locking into position, what should it "lock" into? My choke cable fitting looks fairly new.

Thanks.
Tom M.

[geoberni]

If a Choke Cable doesn't lock, it can be because it's not been properly fitted.
Do you have a Workshop Manual?
In the Morris/BMC one its detailed on page B16 (page 114 of the bound copy) the para titled 'Mixture control failing to lock'
The cable has to be twisted before clamping to the Carb lever.

[simmitc]

There are different styles of choke cable:

Some have notches across the shaft, and these rely on a spring within the body to hold them in position. There is normally a "notchy" "clicky" feel as you pull the cable out and then push it back. If not, then the spring clip may have failed. This type of cable usually has a solid inner which, when twisted, simply springs back.

Others have a groove along the length of the shaft that allows smooth movement when in the "normal" position but lock when twisted so that the groove is no longer in line with a key in the body of the housing. This type of cable is usually has a stranded inner that is flexible enough to allow the knob to turn.

In both cases, the time honoured way of keeping the choke knob out is a clothes peg.

Over the years, as cables fail, a different style could easily have been fitted by a previous owner. I suspect that yours is the first type, and the indentation that you can see is the notch that engages with the spring in the housing, in which cases, rotation is not required.

[myoldjalopy]

The clothes peg is a common 'solution' but, in reality, is a bodge which does nothing for the harmonious appearance of the dashboard

[geoberni]

I knew there were different styles of Choke Cable used over the years, but I thought they all had the twist to lock function.
I didn't know there had been a solid core one. Was that on the MM?

ESM have them as a Series II version in Brown and then a '56-63 and a '64-71 both in Black.
They don't mention a MM version.

[nutmegct]

Thanks gentlemen. As mine seems relatively clean and not shopworn, seems it should actually work properly. That notch in the top of the cable, about two inches back from the end of the knob, must catch on something, but I don't feel any attempt to catch regardless of how far the knob is drawn out.

I've been using the clothes peg(s) as temporary detents; altho' "quaint", I'd rather the system work as designed.

Is replacement a real headache? The removal and replacement of the choke assembly in my 1953 MGTD wasn't fun, as guiding it through the firewall was a bit frustrating and tedious.
Tom M.

[geoberni]

Thanks gentlemen. As mine seems relatively clean and not shopworn, seems it should actually work properly. That notch in the top of the cable, about two inches back from the end of the knob, must catch on something, but I don't feel any attempt to catch regardless of how far the knob is drawn out.

I've been using the clothes peg(s) as temporary detents; altho' "quaint", I'd rather the system work as designed.

Is replacement a real headache? The removal and replacement of the choke assembly in my 1953 MGTD wasn't fun, as guiding it through the firewall was a bit frustrating and tedious.
Tom M.

Following on from simmitc's info, I would just check that it has some tension on it as per the workshop manual. A few moments to try it might save you an unnecessary purchase and replacement.

choke.JPG (113.51 KiB) Viewed 910 times

[nutmegct]

Thank you gentlemen! I'll do the twist tomorrow morning.
Apologies to Chubby Checker.
Tom M.

[simmitc]

I should have added that the notched cable could be twisted twisted to release it, disengaging the notch/clip and allowing smooth return of the cable, but I have always found them to be easy enough to just push back - probably worn over the years.

Replacement of the cable assembly is easy enough once the glovebox has been removed to gain access. Disconnect the battery as you will be working behind the speedo and near the light switches. It may help to remove the speedo, but not always necessary.

[moggiethouable]

i am not recommending this, but I do recall clothes pegs were popular in the 60s.

[nutmegct]

Monday update.

Twisting that inner cable didn't change anything. Knob still won't catch when pulled out and turned.

However, when choke is removed, I notice that the "C" on the knob is actually rotated 90 degrees, appearing as a fat inverted "U" pointing to the floor.

If I twist the inner cable several times, I can right the knob so the C appears normally. Release the twist, the knob turns back and shows an inverted U again.

Is it possible that my relatively new choke (shiny clean and in place when I purchased the car) was somehow installed improperly? Seems the knob should show C when "at rest", and only change to inverted U when the knob is pulled out and twisted 90 degrees to lock.

The plot thickens.
Thanks for your advice.
Tom M.

[nutmegct]

Update a few minutes later!

I've removed the cable from the locking stud at the carb and pulled the cable in and out a few inches with no problem. Put the cable back in the hole in the lock, twisted half turn, tightened the set screw. Knob "C" is now correctly positioned.

But - the knob now won't turn anticlockwise at all - only clockwise. And the four notches on the knob stem still don't catch into anything when the knob is pulled slowly out.

Frustrating!
Tom M.

[myoldjalopy]

Then I am beginning to wonder if you have the right cable for a 1957 car. My SII choke cable has three or four notches (I haven't counted them recently!) but simply pulls straight out and thus locks into place. As yours doesn't, and as you say the cable looks fairly new, it could be that a previous owner fitted the wrong sort, and it actually requires the sort with the groove as described previously by 'simmitc'.
Maybe owners of 57 vintage cars can confirm how their choke locks. What colour is the knob? The SII ones were brown, later ones black.

[nutmegct]

hmmm - and I'm beginning to wonder if I have the correct carb for the car. Take a look at the choke fitting, which is different from that shown in the manuals. The engine was replaced at some time in the past. And interestingly, Moss UK and Moss USA show the correct choke cable for my car (552xxx) is not available.

Morris choke.JPG (413.14 KiB) Viewed 794 times

[myoldjalopy]

ESM appear to have the choke cable for 1956-1964 models, which *should* include your car, all things being equal.
https://www.morrisminorspares.com/fuel- ... -c-p830821

[philthehill]

You do not have the correct original carb for your 1957 car.
Your 1957 Minor should be fitted with a 1.25" H2 carb. You appear to have either a 1.25" HS2 or 1.5" HS4 carb.
There should be a tab on the float chamber with a serial number. That serial number will identify the carb you have installed.
The carb should have no influence on the choke cable.
I would replace the choke cable with the one listed in the ESM link above.

[simmitc]

The ESM photo shows the groove along the length of the shank, so that is definitely a twist to lock cable.

[nutmegct]

The carb tag shows AUC 944, so that's an HS2. Following your advice, I'm ordering the proper choke cable from ESM, plus some other needed bits (passenger side windscreen wiper and blade. Here's the present top and underside of the choke cable knob end. There are actually four notches on the top of the cable end (only one is visible, as the knob won't pull out any farther when the other end of the cable is fastened to the carb). The bottom of the cable end is flat, not round.

IMG_1336.JPG (333.68 KiB) Viewed 726 times

IMG_1337.JPG (304.74 KiB) Viewed 726 times

Thanks all.
Tom M.