Maybe it would help you guys if you saw what you're diagnosing.  Unfortunately, with this website's new format being slower, I'm not sure if my video embedding on the other thread actually worked. 

These videos were originally found on Tony's YouTube page and are in near chronological order.  I'm not sure if cleaning the float chamber was first, but the round plastic HS4 air cleaner was 'earlier' than the later videos, and the videos will give some insight as to possible causes.  And, before anyone asks, I have not altered, changed or modified in any way these videos, not even the titles. 

I downloaded them and now host them on my own YouTube page for purely educational purposes.


 


 


 


At 1:38 into the video, the bonnet is lifted and a current view of the carb, air filter and throttle arrangement is available. 

 


I agree with Dan whole heartedly that it's a real shame that this mini is forced to suffer like that.  This is possibly out of my league...

edit:  Ok, got the videos loaded...  Prob'ly 'splains a lot...


" 6.  Test the needle and jet alignment. Remove the black dashpot cap and plunger (where the oil goes in). Lift the dashpot using the small lift-pin, and let it drop. If no lift-pin, remove the air cleaner and use your finger. It should drop with a small clunk. If not, your jet and needle are not centred. "

Dan, this car (can't remember if it was a 1977 or 1979 or whatever it is) probably has a biased needle.  Assuming that it has a biased needle, and Waxstat jet, there's no jet-centering necessary.  And, I might add, I've never had a Waxstat jet fail - I know many who look down on them, but they can last for years and years and wouldn't cause the problems Tony's allegedly having. 

It's also clear from the video that it's an A+ and previous threads (Robster or Velocity) established that it was a 998.  Remember the thread where we told him to take the tape off of the number in order that it could be read and confirmed.

Assuming Tony really wants help, he's got to be honest about what he's done to it, honest about what he's installed, honest in his presentation and honest about what the car is doing.  My 2 cents recommendation - take the silly stuff off of it, get it running with original equipment parts, then re-decorate it and re-tune it one piece at a time - as you all know, changes to the induction system necessitate changes to the fueling and possibly ignition systems.

If running is being inconsistent, then I would check for a worn throttle shaft. If the carburetor is old and never attended to, this will cause inconsistent running and no adjustment will correct it.

If it is really worn, it can be felt. If not you need to spray starter fluid or something else at the ends of the shaft.

But there could be any number of causes, so proceed with Dan's list first.

First, we need to verify which engine and carb you actually have:
 1.  Please confirm your engine is a 998cc A+.
 2.  Post photos of your carb. I don't think you have a HS2. More likely a HS4

Next tell us what needle and jet you installed when you replaced them.  If your engine is not highly modified, then the standard jet and needle should work pretty well.
 3. Is the jet a Waxstat type or the plain type?
 4. What is the number on the needle - you need to remvoe the needle and read it if you don't have it written down somewhere.

Things to check on your carb.
 5.  The there should be a spring between the idle mixture nut and the jet guide nut. If it is missing, the idle mixture won't stay where you set it.
 6.  Test the needle and jet alignment. Remove the black dashpot cap and plunger (where the oil goes in). Lift the dashpot using the small lift-pin, and let it drop. If no lift-pin, remove the air cleaner and use your finger. It should drop with a small clunk. If not, your jet and needle are not centred.
 7.  Next, verify which spring is inside the dash-pot. Carefully remove the 3 screws and lift the dashpot out. Drain the oil out. Push the dashpot piston all the way up and the top of the damper will stick out the hole where you removed the damper cap. Remove the clip and then slide the piston down and out. Inside, between the piston and the shell, you will find a large spring. Be careful not to damage it and do not modify it in any way - it is carefully calibrated. You should be able to see some faint colouring on it, most likely red or blue. Report what you find and reassemble the carb.

Once you give us this information, we can tell you what to do next.