Choke position in carb mouth

[Catz]

The choke position in the carb on my Amal 389 looks wrong.
With the choke in the off position is it supposed to be at the bottom of the carb mouth blocking off the flow to the needle?
See the picture with the throttle half open and choke position supposedly off.

[JulianS]

That choke is in the on position. Cable is slack.

Choke off when cable tight and the slide out of view.

[Catz]

Thanks for the quick reply.  I thought it was wrong.

[Catz]

No way. Whatever i do with either the choke cable or the spring it always goes to that position. What am i doing wrong? I'm totally lost with it.
So what is to stop the choke lever becoming loose due to vibration? Crap design if you ask me.

[groily]

Check for (correct) spring washer in the lever at the 'bars? 
If the central screw is done up tight and the lever still moves on its own, or very easily, then there's something missing or maybe a mix of non-matching bits on the 'bars.
Should stay up just with friction - I don't think a bad design in this case to be fair (all manual advance and retard cables also work the same way).

[Catz]

You are right, i'm just moaning about it because i'm used to modern Japanese stuff. The wave washer inside the choke lever housing holds the choke closed, i know that now.
The set up on mine is by the frame rail for the seat with a short cable. Thanks for your reply.

[mikeb]

Catz I think your moaning is somewhat justified. Before I bought an A10, I’d never met a vehicle where I had to pull the choke off (I grew up on japanese bikes and British cars). When I first got my a10 running, it got me so confused as when the engine warmed up I thought I was pushing the choke off, only to push it on and have it run super rich. And recently I unknowingly bumped the lever (also on the frame) but only noticed when the plugs fouled. Later mags moved to slack wire advanced to avoid the equivalent. So, pain shared, lesson learned. Would be better to not have a choke at all.

[groily]

I’d never met a vehicle where I had to pull the choke off (I grew up on japanese bikes and British cars).

Not unreasonable what you say! Until I bought a CB900F Honda in the '80s I'd never had anything half so complicated on a m/cycle as a bank of Keihins or whatever they were.

But  . . . the thing to criticise would have to be the Amal-type throttle valve design in general, where the 'choke' is more correctly described as an air slide. (As opposed to the sort of enricheners you find on carbs with butterfly throttle valves etc.)
I've very seldom had a Monobloc that was ever helped much by an air slide for starting if well- tickled, even in cold weather, and the same has gone for the half dozen or so Concentrics I have had over the years.
At the moment, I am running 5 Monoblocs with their air slides removed and the cable holes blanked off to prevent air being sucked in.
Consequently there is a box of slides and springs  from 376 and 389 Monos, 626 and 928 Concentrics, plus a pre-monobloc or two, sitting on the Carb Shelf in the shed, to be dished out to any subsequent owners who feel the need for them.

[Catz]

Thanks for your replies lads, i thought that i might have committed one of the Seven Deadly Sins by moaning about the A10 carbs. Glad i'm not alone.
I don't think i'm up to removing the offending item just yet. I'll wait until i've clocked a few miles up and decide. You never know i might get on with the thing.

[Triton Thrasher]

When people rode these things because they had to, it was common to see the air lever held open by a loop cut from an inner tube.

I’m not going to say it’s a “bad” basic design: it harks back to pre-1930 two-lever carburettors and it’s a simple way to enrich the starting mixture.  I find life to be simpler with the contraption removed though.

No offence, but you’re not a mechanic, you’re a bike rider.  You have bought a 60+-year old vehicle and are making big assumptions about how to use it. 

[Greybeard]

I have only had to use the choke on my bike in extremely cold weather. Normally, after a generous flooding of the float chamber the engine starts first time, (usually). I have the choke lever friction set tight so it cannot release the cable. The mixture is a bit rich which helps the easy starting but the engine runs very nicely so I'm happy. Oh, another factor maybe, the bike has a K&N air filter.

[Catz]

the contraption

Like it.

I have the choke lever friction set tight so it cannot release the cable.

Good idea.

[Black Sheep]

Old British bikes are different from modern bikes. Some of us have 50+ years experience of them but at some point our bikes are going to be handed over to riders who don't know anything about them. What's needed is a comprehensive guide to owning and riding old British bikes.
Anyway, the choke is useful and it works ok. The only bike I have that never needs the choke for starting is the Velo. But Velos are odd anyway.
I have found it useful on a long fast trip recently where the A10 was running was running lean at Motorway speeds so was able to partially close the choke and get it running properly. A main jet increase from 280 to 300 was the solution. Modern petrol...
Of course, riding in the frozen North makes the choke quite useful for cold starts. It's snowing outside just now.     

[Rex]

I'll agree with that. I like chokes on Amals, and all my bikes so-equipped (particularly the A7) like a bit of choke on the first start of the day.
I could never understand why some advocate removing the whole she-bang...why would you?
Then again, if we wanted modern-bike simplicity we'd all just ride one of those nice Honda's and be done with it.

[Swarfcut]

 Too right Rex. Anyone  recently priced  up new diaphragms and slides for any all singing and dancing constant vacco riceburner carbs?  Simple AMALs look good value in comparison....

 Swarfy