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Automatic choke/twin choke

Posted: Fri Jan 10, 2020 2:06 pm
by Murray.arnold
Good day all.
Our Moggie, Bella, to give her her proper name, has standard carb with manual choke. She start on our drive and its a hill start with having to stop to look, on the hill before pulling out. You can imagine how awkward this is. Pulling on the choke, slipping the clutch and getting the revs right. Ok so for myself, a seasoned classic car driver, this is all managable. But shes not mine. She the wifes. And this is a drama.
So i want to change her to a webber with auto choke. Not a performance upgrade. Just a drivability upgrade. Need some direction here guys. I have binned the SUs on my v8 mgb and my tr6 in favour of webbers. In both instances it was 100% the right thing to do.
Who can help so my wife can enjoy her car.

Re: Automatic choke/twin choke

Posted: Fri Jan 10, 2020 5:03 pm
by philthehill
I must say that I have never had a problem with the choke operation of a SU fitted to a Minor.

All you do is pull out the choke and leave as is till the engine is warmed up and then push the choke in.

Does your choke cable not stay at the position it was pulled out to?

I have experience with 28/36DCD and 45DCOE carbs on 'A' Series but they have manual chokes.

Looking at the smaller single and twin choke carbs they appear to have manual chokes which puts you back to square one.

Here is a twin barrel with auto choke but it is a bit large for the Minor - even the 28/36 is too much for a standard 948cc/1098cc 'A' Series.

https://www.ebay.co.uk/itm/New-GENUINE- ... Swny1ajt4c

Here is a auto choke twin barrel carb with auto choke which is more suitable for the 'A' Series.

https://www.ebay.co.uk/itm/Weber-DGAV-t ... SwyqleFHOc

Whichever carb you choose You will need the special inlet manifold as well.

Re: Automatic choke/twin choke

Posted: Fri Jan 10, 2020 5:31 pm
by myoldjalopy
The probem appears that the choke won't stay out on its own. Some have used the tried and tested (although rather inelegant) clothes peg (or two) solution to keep the choke out but, really, the choke knob *should* stay out on its own. However, this doesn't always work, especially if the choke cable has been fitted to the carb without twisting the cable about half a turn clockwise, which is how it is supposed to allow for different settings. This should allow the choke to be fixed in any position...the knob itself may need to be twisted to get it to 'catch'. Loosen the cable at the carb and twist it as the manual suggests and all may be well. So I would try and get the choke working as it is meant to before splashing out on some fancy and totally unnecessary 'auto choke'..........

Re: Automatic choke/twin choke

Posted: Fri Jan 10, 2020 7:38 pm
by jagnut66
Does your choke cable not stay at the position it was pulled out to?
Hi,
I have never known one of these chokes (be they, original, new original style or eBay type replacements) to stay locked in position when pulled out yet.
I have learned to just keep the ever reliable clothes peg on standby and not worry what it looks like :wink: .

It would be interesting to know what the Webber does for performance and fuel consumption on your engine. What size is it? 948cc or 1098cc?

Best wishes,
Mike.

Re: Automatic choke/twin choke

Posted: Fri Jan 10, 2020 8:16 pm
by Murray.arnold
Ive had an idea. I have bike carbs. I recon i could use a pair of bike carbs. Based on HP requirements they should maybe work. The moggies only 50hp. I have a very tallented nieghbour who could modify the inlet for a more modern bike carb. Hmmm. Maybe onto a good conversion.

Re: Automatic choke/twin choke

Posted: Sat Jan 11, 2020 11:44 am
by simmitc
I sympathise with the problem, but question wheter the Webber is the right solution. Years ago, I fitted a Webber to a Minor for improved performance. A lot of expense, a lot of work with the manifold. Even after adjustment on a rolling road, the damn thing was incredibly tempermental and never delivered the smoothness of the SU. After a few months, I reverted to the SU and have stuck with them ever since.

In the old days of chokes, it was normal to allow the engine to warm up before moving off, and a couple of minutes waiting on the drive might work wonders. everyone has become so used to computer controlled fuel injection etc that it's been forgotten how to drive simpler cars.

Re: Automatic choke/twin choke

Posted: Sat Jan 11, 2020 3:23 pm
by midget
I use a Marina choke cable, perfect ,but I'm sure others will be a straight swap too.

Re: Automatic choke/twin choke

Posted: Sat Jan 11, 2020 9:54 pm
by BobHood
From memory, when I had a manual choke on a car I used to pull the choke out and twist the knob a quarter turn one way or the other. This locked it in that position till I wanted to reduce the amount of choke. Then I simply twisted it back, pushed it in a bit, and twisted it again to lock it in position. As far as my memory goes, that was standard practice back in the day, when all cars had manual choke.

Re: Automatic choke/twin choke

Posted: Sun Jan 12, 2020 5:00 pm
by myoldjalopy
Yes, that sounds pretty standard. Regarding use of the choke knob and the fitting of the choke cable, the Minor Workshop Manual states:
"It is essential for the proper functioning of the ratchet device that there is a rotational bias on the cable when it is clamped in position to the carburettor mixture control lever. To ensure this the inner cable must be given an initial twist of approximately half a turn, in a clockwise direction, looking at the end of the cable, before the clamping nut is tightened up."
Failure by previous mechanics to observe this procedure will have left many an unsuspecting owner resorting to the clothes peg trick.....

Re: Automatic choke/twin choke

Posted: Sat Jan 18, 2020 6:07 pm
by MikeNash
In view of your problems, this afternoon I watched my cold start closely.
My '63 Traveller had cold soaked to 3C in the garage; outside in the sun it was 5C. I pushed it out backwards out of the garage and started on full choke and after manoeuvring in the yard and after 30 seconds running time I'm edging out onto the A343. It's a 30 mph zone but with a bend and with power cable pole in the way, its always a case of move slowly out and into reversing back quick when something's coming. By now I've the choke half in and she's still running fine and reliable. Then its foot now for a quick cross of the road and the choke's released down to about 4 notches and at about a quarter of a mile its down to a couple of notches out that give the fast tick-over.
With my choke (which I think is original) you can feel the "ratchetty action" as it moves - no rotation is necessary. As I say above, the first two notches don't operate the choke at all but just speed up the tick-over using the cam mechanism at the side of the carb. At a quarter of a mile we're climbing Hurstbourne Hill which gets to 1 in 7; when cold this is 2nd gear (25 mph) and when hots its 3rd gear (30mph) but its all manageable and reliable. All Morris' are different but my thoughts are that if you get the choke cable to function correct your Good Lady will find it OK. My ancient mother drove my car for years and hadn't a clue what a carb was - and it worked for her!
MikeN.

Re: Automatic choke/twin choke

Posted: Mon Jan 20, 2020 7:45 pm
by twincamman
I think they changed from the 'ratchet' type to the 'twist to lock' type when they dropped the pull-start.

Re: Automatic choke/twin choke

Posted: Tue Jan 21, 2020 5:29 pm
by MikeNash
Ah, thanks I didn't know about the change. Hope I didn't muddy the waters too much above.
MikeN.

Re: Automatic choke/twin choke

Posted: Tue Jan 21, 2020 7:46 pm
by Murray.arnold
All interesting. But i am now set on a single modern bike carb. Why not. I wull simply take the current manifold and get the alloy welding/ fabricating guy across the road to manufacture the connection between old and new.
I will keep everyone updated on the functionality of the conversion.

Re: Automatic choke/twin choke

Posted: Wed Jan 22, 2020 12:07 am
by StillGotMy1stCar
Why not go the whole hog and fit a bike head as well :D
https://www.youtube.com/watch?v=H70vEq_FMvs
Regards John

Re: Automatic choke/twin choke

Posted: Wed Jan 22, 2020 9:31 am
by myoldjalopy
....and some handlebars in place of the steering wheel too..?

Re: Automatic choke/twin choke

Posted: Wed Jan 22, 2020 10:34 am
by Murray.arnold
You guys are killing me. Stop it. 😀😀😀😀. I do however have a spare 2.0 blacktop zetec engine. T9 box and cbr 600 carbs all set up. Just waiting for the right car. Hmmm. Ha ha. Dont wory. I wont touch the moggie.
I have my ey on a ford 100e. One here in croatia for sale.

Re: Automatic choke/twin choke

Posted: Wed Jan 22, 2020 10:37 am
by Murray.arnold
Heres mywifes car. The one in question.

Re: Automatic choke/twin choke

Posted: Wed Jan 22, 2020 11:18 am
by myoldjalopy
Sweet! 8)