Choke cables - are they obsolete for the Morris Marina?

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mickthefitter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by mickthefitter » Thu Jul 13, 2017 2:59 pm

Oh. :eh: I felt sure I'd read somewhere that the locking choke cables had a little ball bearing that could fall out. My mistake then. Its a brand new cable that came via Earlpart after the fiasco I had with Moss, phoning them and giving them the dimensions I needed and then getting one 20 inches shorter. The Earlpart one is 4" too long but I knew that when I bought it. They told me. But its what they list for the Marina. I put the cable in the car while the carbs were away, thinking I'd get away with the excess length but then I had to route it at the back of the windscreen wiper motor. With the carbs back on I didn't want to struggle with the column cowling and steering wheel again to take the whole cable out to cut it, but didn't think the extra length would be an issue. The cable returns easily from any position and pulls out okay up to the point where the jets are about to open, but then needs so much force I have to push against the steering column shroud with the other hand for fear of it breaking. Operate the linkage under the bonnet and it seems okay, its just a matter of overcoming the resistance of those twin return springs. Last night I routed the cable over the air filter intake and it was a bit easier to pull the choke out than it was when it was anchored to the clips that held it alongside the throttle cable. So I figure I need to shorten the choke cable by those four excess inches.

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Morris McKinnon
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by Morris McKinnon » Thu Jul 13, 2017 9:13 pm

The choke spring on the carb should be a small coiled type hooked around the linkage pivot to carb body, unless the twin set up is different. The extra 4" to the new cable might be because the mk1 choke is near the bonnet release whereas the mk2 is at the steering cowl so can be cut to fit both mk1 and 2. Maybe other cars had a bearing at the choke lock but I've never seen one.

mickthefitter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by mickthefitter » Thu Jul 13, 2017 9:35 pm

The twin carb set up has one spring for each carb acting on the linkage bar that joins the choke butterfly spindles, the lower ends hooked around the 'tin' heat shield, and a third middle, somewhat weaker spring serving as a throttle return spring, which attaches to the throttle cable trunnion and the lower edge of the heat shield. The Earlpart supplied cable was described as a generic one, but one that customers had no problem fitting to Marinas. Perhaps I should have trimmed it before installation but I had no carburettors to offer it up to at the time. I feel certain a single carb set up would offer a lot less resistance to pulling the choke out.

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Morris McKinnon
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by Morris McKinnon » Fri Jul 14, 2017 8:44 am

Just a matter of finding a spring with the right tension it sounds like. You could stretch the spring maybe but you risk over doing it, I've done that plenty in my time on cars :rolls:

mickthefitter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by mickthefitter » Fri Jul 14, 2017 1:03 pm

I think you said you'd had problems with modern spring tensions before. These ones I've got on the car now came back with the carburettors, bright plated items and new looking, as opposed to some of the stuff I got back plated that was obviously used, like pan head machine screws with chewed slots. Of course my carbs went away with the blackened original springs still attached, never to be seen again. Whether or not the bright springs I've got now are supplied by Burlen, I'm not certain, but I would have thought so. Obviously I'm going to have to have a play around with the cable or springs or both, because something is much too tight.

david painter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by david painter » Fri Jul 14, 2017 1:55 pm

My MGB does not use separate springs on the choke just 2 throttle return spring going to the heat shield
Dave

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Morris McKinnon
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by Morris McKinnon » Fri Jul 14, 2017 6:14 pm

david painter wrote: Fri Jul 14, 2017 1:55 pm My MGB does not use separate springs on the choke just 2 throttle return spring going to the heat shield
Dave
Do the twin set up carbs sometimes have coiled springs for the choke maybe (one each)

mickthefitter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by mickthefitter » Fri Jul 14, 2017 6:31 pm

Begging your pardon, I'm sleep walking again. All three tension springs act on the throttle return, not the choke. Two outer ones on the throttle levers themselves, the middle one pulls on the cable trunnion on the link bar. The choke return springs are actually behind the choke actuating lever on each carburettor itself, not a part of the link bar, and were fitted as part of the carburettor build. They are coil springs but I guess you'd call them of the torque variety. Hard to see what I can do about those without starting to take the carburettors apart.

david painter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by david painter » Fri Jul 14, 2017 7:10 pm

Try and put some oil on the outer part of brass jet tube, when its down. Also where lever is screwed to jet should be a little top hat washer to allow the screw to tighten but lever still to pivot freely.
Dave

mickthefitter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by mickthefitter » Fri Jul 14, 2017 7:27 pm

:thumbup: I'll take a look over the weekend. Just got the car back from having the back box fitted that was supplied by Baz. Mr. Glyn Daft of G&N Cars, Acton Avenue, Long Eaton, refused to take any money off me even though he's had my Marina all day. Reckoned it was only a ten minute job for him and that he enjoys working on the old ones. Top bloke.
WP_20170714_17_53_14_Pro.jpg

MARINAMADBAZ
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by MARINAMADBAZ » Fri Jul 14, 2017 10:51 pm

Looks good mick nearly there now then!
All the best baz

mickthefitter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by mickthefitter » Fri Jul 14, 2017 10:57 pm

Cheers Baz. Now I should have the chance to actually get to know the car!

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Kilroy
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by Kilroy » Sat Jul 15, 2017 7:09 am

It helps to apply oil or grease to the choke cable - even if it is new.

You should be able to remove the inner whilst leaving the outer in place if you wish to get some thin oil down there.
3-in-1 oil is good.

mickthefitter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by mickthefitter » Sat Jul 15, 2017 7:43 am

I reckon that's what I'm going to do. Disconnect at the carb end, pull the inner through the outer a bit, find a way of shortening it and put some lube on it. When I worked in an electric cable factory and used to make up brake cables for cable winding stands, the cleanest way I found of chopping inner cables to length without splitting the strands was a sharp cold chisel on a hard surface. Can't do that under the bonnet of the car, so I will have to use side cutters!

mickthefitter
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Re: Choke cables - are they obsolete for the Morris Marina?

Post by mickthefitter » Sun Jul 16, 2017 4:56 pm

Well, I've chopped about six inches off the inner and outer choke cable this morning, re-routed it the way it should be, over the top of the windscreen wiper motor instead of round the back, touching the inner wing, as it was, and I'm happy to report that the choke control is a whole lot easier to pull out to the full extent now, although I did also run some 3-In-1 type oil into the cable while it was freed from the carburettors. I do feel though that the extra length and indirect routing did have a big influence on the resistance on the cable. The downside, alas, is that the choke knob barely locks and wants to fly back in again now, just like it did with the manky old choke cable on the car before I bothered to change it....oh well, back the the clothes pegs then. :wtf:

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