TR4/4A SU-HS6 Carb "Choke" Issue--My TR4A

[KVH]

SU-HS6 Carb "Choke" Issue--My TR4A

Something's happening here, and it isn't exactly clear


Yesterday my choke cable, at the knob, was frozen as is welded in place. Absolutely would not pull out.

I oiled the carb shafts, manually rotated them, and then it would pull out a little bit.

I then loosened the cable set screw and adjusted the cable by rotating the shaft a tiny bit, then retightening. It worked a little better.

This morning it was near frozen again, until I rotated the shafts manually and tinkered with it.

What's going on here? Is there some trick to the cable position? Is a spring or something binding somewhere?

I've been in TR4s where the cable pulls out smooth and easy. Mine has always required a gorilla grip.

 

[poolboy]

Re: SU-HS6 Carb "Choke" Issue--My TR4A

I'm not sure if this applies to what you have there, but there are some choke cables that allow you to twist the knob and lock the choke in that position until you "counter twist" the knob.
It's some sort of locking mechanism in the cable amd I'm not sure that all (replacement or original) have that feature.

 

[Geo Hahn]

Re: SU-HS6 Carb "Choke" Issue--My TR4A

Some choke cable thoughts --

The locking mechanism is a sort of quarter-moon piece of metal (tiny, maybe 1/16" x 3/16") that will usually fall out completely if the cable is withdrawn well past it's usual position. I suspect its loss often goes unnoticed, thus many chokes seem to lack this feature. Can be replaced with a bit of fiddling, I have even made one when the dropped bit was swallowed by that black hole that exists in all garages.

If you haven't, I would certainly disconnect the cable from the carbs and try both the linkage and the cable to see which is the culprit in the binding.

If the cable, it may have a kink or other bad spot.

For What It's Worth -- enjoyed the CS&N reference.

 

[Moseso]

Re: SU-HS6 Carb "Choke" Issue--My TR4A

Kentville --
"Somethin's happenin' here. And it 'AIN'T' exactly clear..."

Geo --
Buffalo Springfield. Prior to CS&N.

I know music. Sorry I can't help with the choke cable...

 

[Geo Hahn]

Re: SU-HS6 Carb "Choke" Issue--My TR4A

Oops, quite right. Same singer, different group. Man, the 60s are still something of a fog.

 

[Perrymip]

Re: SU-HS6 Carb "Choke" Issue--My TR4A

And I thought along it was "what it is ain't exactly clear." Goes to show:

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]the 60s are still something of a fog[/QUOTE]

That's why we roam Ebay looking for Lucas period lamps.

 

[sp53]

Re: SU-HS6 Carb "Choke" Issue--My TR4A

Hi kentvillhound when i first read you post my first thought was that you did not have a ground strap hooked up and you choke wire was the source of grounding and it was welding itself together.

 

[NutmegCT]

Re: SU-HS6 Carb "Choke" Issue--My TR4A

Based only on my experience with the H6 (not HS6) carbs:

Detach the cable from the carb linkage. Find out if the binding/seizing is in the cable itself, or in the carb linkage. That'll determine the location of the suspect problems.

As other have mentioned, sometimes a "twist to lock" feature has become suspect itself.

When attached, the cable is pulled out about 1/2 inch first, which *only* moves the fast-idle cam. If that cam is frozen or mis-adjusted (in technical terms, "out of whack"), there's the suspect.

After that first 1/2 inch, further pull actually lowers the fuel jet at the bottom of the carb. So with the cable detached, see if the fuel jet can be pulled downward with just the strength of your fingers on the jet linkage. If you can't lower the jet by hand, there's the suspect.

There should be a bit of "play" in the carb linkage arms themselves. They shouldn't be rigid or tight in their "hinges" (pivot points). Some folks try to tighten up all the linkage arms, which actually makes the linkage almost impossible to move. If they're tight, there's the suspect.

Several BCF members mention that the choke cable is a bit easier to pull out, if you push down on the gas pedal an inch or two. That relieves tension on the throttle linkage. If that linkage is tight at the throttle, there's the suspect.

As a French police captain once said ... "Round up the usual suspects."

Hope this helps.
Tom

 

[LBCs_since_1988]

Re: SU-HS6 Carb "Choke" Issue--My TR4A

Kent, I've got the same issue. It's not you carb linkage. It's definitely your choke cable. I'm betting it's an "exact" repro. Somebody must have made a bad batch. It looks right and pushes in easily but is a nightmare to pull out.


Aaron