Technical Fast idle/choke usage

[Didge3]

Now warmer weathers are happening I'm using less choke and using it for a shorter time. However I have noticed that my choke basically gives me two options, when the engine is stone cold I run it at half choke and it idles at 1800rpm, if I reduce the choke it'll stall or run rough at ~700rpm.

Once it warms up even after about a 5mins I can bring it down to about 1200rpm on literally a tiny amount of choke, such a small amount its almost closed. As the engine warms the idle rises with it but until its about 60c if I close the choke it'll idle rough. So when its up to around 50-55c my idle has gone back up to 1800 and if I push the choke in even a millimeter it starts to splutter.

So basically I think something needs adjusting, so the choke is more progressive maybe? Because between half choke and almost closed nothing changes, I can push it in quite a way without any change in the rpm

It's not really an issue but I feel I just waste fuel with the choke operating too high when the engine is warming and I can't adjust it.

Sorry if that doesn't make much sense, but thanks for any help

 

[Bartpanda]

Choke needs adjustment or there is a small air leak somewhere.

Choke should work smooth through the engine revs from open to closed, with two "noticeable "stages, you should be able to "feel" it when pulling the choke. In the choke arm there are two holes and a small steel ball with spring under the choke arm. When the hole is over the ball, the ball "jumps" into the hole and it gives the "feel" of a stage of operating the choke. the idea of starting the engine using the choke is to pull it fully, start the engine, as soon as it starts you reduce the choke to the first hole/stage when its cold outside or you can try immediately to the second when its warm. That is the theory but every engine works a bit different considering its conditon, the outside temp clean/dirty air filter ignition timing etc....

those holes in the green circle:

 

[Dragon Man]

hmm when i was running carb, my choke had 3 settings.. full on, half and fast idle.

full on.. all the way out.. half was the first click but fast idle was just a tiny bit pulled out.

my idle was set too low, i had to use the chokes fast idle all the time. it never engages the choke flap, just brings the revs up..

have you checked the vacuum solenoid on your distributor? make sure the thing holds a vacuum and actually moves the points when a vacuum is present.

this was all that was giving me issues till i fixed it.

 

[Didge3]

I would say I can only 'feel' one setting on the choke, which would be half choke, you can feel it sit in place, which is what I pull it out to when starting, and then I start to push it in, but its not really a linear thing, from full down to half it does operate normally and reduce the rpms as you press it in, but from half to almost closed it doesn't affect the engine until just before the choke closes. I feel like the fast idle is set too high? Surely a cold engine at half choke should be below the 1800-2000rpm that mine seems to sit at?
I'd rather it be more like 1500 so I can at least sit at traffic lights etc when the engine is cold without it running at 1800rpm.
Once warm the engine actually idles at 1100-1200rpm, although this falls to 1000rpm with electrical load.