Choke Cable

[McMuttley]

Having installed the refurbished carbs (HSU6), I re-attached the existing choke cable.

 

As before refurb, the choke knob only pulls to two very short stops, is very stiff and a definite stop; whereas when not attached to the carbs I can see 4 or 5 stop notches when pulling it out.

 

I have read of more than two choke positions. On mine the second position is about half way on the cam - should it go beyond this point - or are there simply two choke settings

 

Also it is not now going back to the start position when pushed back in, so I suspect a kink and / or frayed inner cable catching on the reinforcement.

 

I am therefore going to get a new choke cable (not cheap !), when installing, will there be just two stops, or should I be looking for more.

 

Thanks

[Don H.]

I can only pull my choke two clicks, Austin. But that's enough. My car will fire immediately from cold when choked to that second click.

 

After about three or four years now that Bowden cable is finally getting loose enough I don't fear breaking the knob when I pull it. Returning the cable is a simple matter of turning the knob a quarter turn to move the ratchet stops off fhe pawl and pushing it in.

 

I'm running my original AUC878 H6 carbs. Maybe Bob will come in -- he runs HS6 carbs on his TR3.

Edited April 26, 2016 by Don H.

[TR 2100]

Back in the days, there were two settings for the choke.

Sixpence or, more usually, two bob (or a ha'penny for the cheapskates).

That's because the cable wouldn't catch on the notches!

 

AlanR

[Fireman049]

To make the ratchet work you need to disconnect the cable trunnion from the carb. and turn it in a clockwise

direction a couple of turns and then refit it.

 

Tom.

Edited April 26, 2016 by Fireman049

[Don H.]

...I am therefore going to get a new choke cable (not cheap !)...

 

What do they cost over there? Here a TR4-style HS6 choke cable is less than £20.

http://trf.zeni.net/TR4-GB/35.php

[Graham Harris]

I rebuilt my cable using a pushbike brake cable, best with nylon covered inner.

The stiffness in the choke can be relieved if you make sure the main jet is well lubricated with a silicone type gel where it slides up and down in the carbie body .

Graham

[Lebro]

There should be 4 or 5 "click stops" as you pull the choke out. If you are getting less than this then the cable has been terminated at the carbs too far from the end, or if it is at the end of the cable then the cable has been shortened. Fix for this is to shorten the outer of the cable a tad.

As Tom says you should put a deliberate twist in the cable as you fix it to the carb in order to force the knob anticlockwise otherwise it will not stay at the "click" positions.

Adjustment of the choke, & the throttle advance with choke screws is fun (not) & can take quite a while to get it right.

 

I start my car from cold using 3 clicks (4 if it's really cold), but almost straight away drop down to 2 clicks, then drive car, dropping to 1 click when temp starts coming up, then no choke soon after that (by which time it will tick over nicely)

 

Bob.

[RobH]

We did this topic a few months back where someone was having difficulty starting, as the choke was not opening fully. I don't know about clicks but the choke knob on my car comes out a full 2 inches from the dash for max choke and yes it is very stiff indeed after the first inch of travel (its a solid inner wire, not stranded cable). You might just have to pull harder Austin.

[McMuttley]

Thanks John - I definitely have a lot less than 2" no matter how hard I try!

 

It is the same as this £41 offering from Moss, with about the same free cable at the end, but in far grubbier condition.

 

http://www.moss-europe.co.uk/choke-cable-inner-outer-400627.html

[Lebro]

The Moss one above looks to be correct. What is stopping it coming out further - is it the carbs, or something wrong with the cable.

The worst part of the standard choke cable design is that the end of the solid part fouls the heater, resulting in a sharp bend just as the flexible part begins.

 

The carb end of the inner cable should finish in a clamp, which links onto the carb choke lever. If you detach it, how far does the choke knob come out then ?(& how many clicks)

 

Bob.

[Ian Vincent]

The worst part of the standard choke cable design is that the end of the solid part fouls the heater, resulting in a sharp bend just as the flexible part begins.

 

Bob.

To the extent that the solid part on mine fractured and rather than spend £54 (which is approx how much I remember It costing from Moss) I cannibalised a spare cable that I had in the garage to accept the original TR knob and bezel. It means that my choke is relatively easy to pull out and can usually be persuaded to stay put.

 

Rgds Ian

[Guest]

Back in the days when my hair was a lot darker than today(...) I owned a Spitfire 1500 with more or less the same problem: it was nearly impossible to pull the choke. The Spit has the advantage that you actually SEE what happens when you pull the choke. The front hinged bonnet gives you enough 'room' to look over the top of the front window into the engine bay. I noticed that the force used on the dash knob wasn't the same at the other end: I was able to pull and pull harder but nothing happened at the other ends.

 

Finally I found out what happened: the inner and outer cable were tangled somehow. Every time I pulled the cable, the outer cable was pulled as well and stopped by the back of the dash. I'd completely distroyed the outer cable...

 

A new cable from a bike repair shop did the trick... Less money than the Moss equivalent and it worked!

 

Menno

[Fireman049]

I get four 'notches' when I operate my choke. It's all up to fine adjustment when setting up the choke cable.

Don't forget, the first 'notch' should only operate the jet cam giving you increased revs. and no choke.

My outer cable finishes flush with the clamp so giving me full choke operation.

 

Tom.

[McMuttley]

Here you go Gents

 

(apologies for the shiny bling, but that's what a set of carbs looks like if the engine never runs !)

 

 

Pic 1

Choke not applied. The cable is taught, but not overly tight, the kink is permanent - maybe it was too tight in a past life ?

 

Pic 2

Choke pulled out 2 notches - only mid way along the cam

 

Pic 3

Using more force I can now get to notch 3, about 2/3 around the cam, but no further.

 

The spring return isn't the strongest, but (i) I haven't checked if I re-assembled the carbs and linkages properly and (ii) as they haven been used or lubricated, they may be stiff. (I have squirted plenty of WD40ptfe spray down the choke cable though)

 

 

Without the cable attached to the carbs I can pull it out 5 notches plus with no resistance.

Edited April 27, 2016 by McMuttley

[Lebro]

Does the cable termination swivel in the carb choke lever, or is it solid

If the latter, the further you pull, the more out of line the cable gets.

 

Bob.

[McMuttley]

Hi Bob,

 

The clamp attached to the carbs - i.e. the long hexagon nut?, isn't tight to the car assembly, but loose, so yes it does allow the cable to stay vertical when pulled - pic 3 shows the hole in the nut facing toward the choke cable when at notch 3.

 

I can manually push the choke lever on the carb further up, but pic 3 is as far as the cable will pull it.

[Don H.]

If your helper works the dash knob and you work the carbs at the same time, how many clicks can you get?

[Lebro]

Try lubricating the cable, & the linkages on the carbs, including the cam faces. It should not be that difficult to apply full choke with the cable.

 

Bob.