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1970 MGB Choke cable.

Posted: Fri Apr 27, 2018 8:32 am
by Paul Harris
Sorry to be pain with my inane questions but latest thing to aggravate me is my choke cable !

The car came with the incorrect (and frayed) "T" handle choke cable which I replaced with the proper 1970 style large round type with the fan symbol on.
This came from a respected MG supplier and is a horrible cheap nasty thing which is very difficult to operate as it is very stiff and gritty feeling in operation and getting worse despite silicone lubricant.
The actual carb levers are fine and work smoothly, the cable has nice easy bends in it and I can see no reason why it should not work properly.
Anybody else had this problem, or recommend a better type of choke cable ?......the T handle one perhaps ?
Cheers,
Paul.

Re: 1970 MGB Choke cable.

Posted: Fri Apr 27, 2018 9:18 am
by Peter Cresswell
Hi Paul
The problem might be that the T handle choke cable is designed to go over the top of the HIF carbs used on the rubber bumper cars. The cable for the 1970 cars with HS4 carbs runs underneath the carbs.
There are two cables available for a 1970 car - one has a 'C' logo and the other has a 'star' so correct cable for a 1970 car with HS4 carbs is AHH6725 with a C logo or BHH653 with a star logo. Which is the correct one for your car will depend on the chassis number - and I haven't found a date for the change! Brown & Gammons are listing both types as in stock; Moss only have the 'Star' type in stock at the moment, but I haven't looked at other suppliers sites.

Re: 1970 MGB Choke cable.

Posted: Fri Apr 27, 2018 11:55 am
by Paul Harris
Hi Pete,

The T handle one was obviously wrong and in a bad way but it still worked better than the "star" one which I believed to be correct for my GT which was made about 0ctober 1969. As you say, I couldn't find a change date from the C marked variety either !

The star one is really of very poor quality (despite coming from respected MG parts firm) but that said it's hardly rocket science and off the car, the cables seem to slide well enough. Likewise, the action of the levers at the carbs seem good, especially now I have replaced the springs from a hardware shop with the proper ones. As I said, the route of the cable is "lazy" and I can see nothing obviously wrong.
None of my previous rubber bumper B's have required a gorilla to pull out the choke, so perhaps that's it...the HIF choke operation is simply better !!!
Back to trying to get the speedometer securing bracket thumb nuts (what a contradiction in terms!) back on !

Re: 1970 MGB Choke cable.

Posted: Fri Apr 27, 2018 1:55 pm
by Peter Cresswell
Hi Paul
Take a look at this page from the Moss Catalogue. It shows how the choke cable should run for a 1962-72 car.
https://www.moss-europe.co.uk/shop-by-m ... 62-72.html
Have your SU Carbs been changed at some time? You mention HIF carbs, the correct ones for 1969 are HS4 and I'm wondering if someone has just bought two HIF carbs and used the linkages from the HS4s. The length of the operating levers might then be wrong making the choke heavy to pull out. In the diagrams the HS4 lever is AUE180 and the HIF is AUE587 and looks longer.

I too found it nearly impossible to get the thumb nuts onto the back of the speedo when it was in the dashboard, so eventually I modified the hole in the dashboard by putting two cut outs into the side of the hole at about twenty to two. It was then possible to put the bracket on and the nuts loosely, along with the speedo cable and wiring, push the speedo into the hole, then twist it to quarter to three, and finally do up the nuts. The cut outs were hidden by the bezel.

Re: 1970 MGB Choke cable.

Posted: Fri Apr 27, 2018 4:16 pm
by Vic Butler
When I ditched the HIF4's for HS6's I used the same choke cable and have had no problems.
. Vic Butler

Re: 1970 MGB Choke cable.

Posted: Fri Apr 27, 2018 4:37 pm
by Paul Harris
Thanks chaps.

Bit of a mystery.

XYY has the correct HS carbs for her year and the linkage is as Peter has kindly attached from the Moss catalogue. There are no acute bends other than the lazy 90 degree one where the cable runs from the bulkhead up the the carbs.
It works well enough but seem "all or nothing" when you pull it out...not smooth as I recall from any of my past B's or Midgets.

Speedo back in and tightened up. What a faff. Managed it just...it's far right nut that's the problem...spot of grease on finger got it eventually and my neighbour has learnt a few new words.

Only had to be done because some muppet in the past installed the wrong overdrive gearbox not suited to the 1280TPM speedo !

Re: 1970 MGB Choke cable.

Posted: Fri Apr 27, 2018 4:40 pm
by Paul Harris
ps.....that's a brilliant mod for the speedo Peter....wished I had thought of that !
P