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MG Midget and Sprite Technical - Accelerator cable connection SU carbs - detail

Good afternoon to all,

MKIII, 1973, standard HS2 SU carbs.

How exactly the connection of accelerator cable to the carbs looks like? On my carbs is some strange home made type of the connection from one of the previous owners and I decided to fix it during my carbs refresh process...

In web catalogue of one of usual providers I can see all the bits needed (see the picture attached), but I struggle to find or imagine how the cable is attached to these.

I expect that the trunnion (17) should be able to rotate freely in the lever (16) to compensate changing angle when cable moves up and down, am I correct? Is the cable just tightened between washer (18) and nut (19) as indicated in the drawing? Would this be strong enough and would this not destroy the cable when tightened?

Can you please describe (or show on the photo, if possible) how should the connection look like?

Thanks in advance,
Stepan


Stepan Marek

Yes the cable is tightened as you describe. The washer (18) is made of copper and the cable passes through a hole in the trunnion. The trunnion moves freely in the lever and is held at the other end by a split pin.

You set it up by allowing a .015 gap (feeler gauge) between the top part of the trunnion and the heat shield. The connectiong lever on the cross shaft then just touches the bottom of the slot on each carb spindle. This is done after you have balanced the carbs.
Bob Beaumont

Thank goodness I didn't reply first. I would have been completely wrong!
I guess it's different on 1500s?
Welcome back Stepan, it's been a while since we saw you.
Greybeard

Bob,
Thanks! Now I understand it - the trunnion has two holes! One for split pin and one for cable. I did not know about the hole for the cable as it is not visible in the drawing.
(Now I feel like an idiot, but happy idiot...)
Mystery solved, thanks. Now I only have to find the same trunnion on local market as paying the postage from UK web shop for one little piece like this is a nonsense...

Stepan
Stepan Marek

Hi Greybeard,

Thanks. I do not post too often, but read a lot :)

This forum is always useful, I am happy you all keep it alive.
S.
Stepan Marek

Greybeard, yes it’s slightly different on the 1500 but works in a similar fashion
Chris Madge

Interesting Chris.
On my car the cable terminates with a brass nipple in a yoke which is pinned to the quadrant. The other end of the quadrant has a rod linkage to the carbs.
Adjustment is via a screw adjuster.
It works well but I have to consider that it might not be original, although Haynes suggests it is, in concept anyway. The cable itself is a Venhill replacement.
Greybeard

Stephan,
just adding to what Bob has put, the Driver's Handbook has drawings and instruction on setting up too (gives 0.012" (0.31mm) rather than 0.015" but I sure either would do) and setting carbs up.

I doubt you'd get a copper washer now but again it doesn't matter.
Nigel Atkins

Greybeard, mine looks like the picture in the Moss catalogue

Chris Madge

This thread was discussed between 23/02/2020 and 24/02/2020

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