[Solved] Iris BC2HP Brush Cutter: Carburetor Adjustment After Unintentional RPM Screw Alteration

Hello, I have a brushcutter like in the subject (Chinese scythe). I have a problem with it, namely when I mowed with the scythe, it walked normally only after about 20-30 minutes of mowing ordinary grass, so it was not too hard, the scythe went out by itself and it was impossible to fire it again. Only after waiting a day, the two scythe fired without any problem.
Trying to remedy it, having no experience, I started to play with the carburetor and RPM screw (my mistake). Now the scythe does not walk as it should, it smokes and previously it hardly smoked at all. The fuel mixture is the same before I toyed with the regulation. In addition, the circular head slowly rotates, without adding gas.
I would ask for the help of experienced people on how to adjust it, below are photos of the scythe. Unfortunately, I do not have the manual, it is lost somewhere.

In advance, let me just mention that I took it apart and cleaned it, and so did I.

If you smoke and choke at the same time when you go into speed - too rich mixture, too much fuel, a screw with a spring is used for adjustment.
I have set it many times - no philosophy, I take a screwdriver and go to mow, fire up, try to mow, then using the trial method: if I wind the smoke, let's say 1/8 of a turn, and an attempt to mow, if it seems weak and does not turn well, unscrew it minimally. I know that the method is not professional, but whenever I adjusted it according to the instructions that are all OK somewhere on the forum, it fired well, but when trying to mow (under load) it turned out that it gets weaker, it gets too little fuel and it was necessary to slightly unscrew the adjusting screw.

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In addition, the circular head slowly rotates, without adding gas.

To adjust the second (top) screw - unscrew it so much that the engine at idle runs evenly and at the same time the head with the line does not spin.

It is of course unnecessary to add that the entire adjustment makes sense if the scythe is operational: compression, spark plug (break, spark), proper (tight) connection of the carburetor with the cylinder.

Thanks for the answer and tell me whether you can adjust both screws, the one with the carburetor spring and the idle speed on the scythe, or before the adjustment, it should be turned off. And is there a risk of incorrect or not fully adjusted carburetor adjustment?

As for the smoking, as I wrote in the subject, she did not smoke almost at all before playing with regulation, but only started after playing. A was working and running on the same fuel mixture (25: 1) as before, so I guess it's not the mixture's fault.

The 25: 1 mixture is ok, all Chinese work on it.
The adjustment is made with the engine running, you start it, press the gas to full throttle several times and you can see if it goes into revolutions well, it would be practically impossible to do it when it was turned off.

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And is there a risk of incorrect or not fully adjusted carburetor adjustment?

In the long run, of course, it is harmful to overheating, seizing the rings with carbon deposits, with too rich a mixture it will eat fuel like a dragon, with sales, it will be weak, it will choke, fade out - just not a job.

I have an identical scythe 6th season and contrary to popular opinion: it is not so bad, despite the fact that it works quite well, I only replaced the clutch (the spring broke) and from time to time carburetor adjustment I do not know if they all have it.

I took up adjusting the carburetor for now. I noticed that in one position the scythe walks like crazy after adding gas, in another it suffocates it. I do not know if I should leave this position as crazy, because I will wear out faster? Should I maybe just leave the prop in a place like this between running like crazy and choking it?
Another thing is that it continues to kick, no matter what position I put the screw in.

Edit

I screwed it in completely and twisted it 1.5 turns. When I was mowing it seemed to work well, but after about 8 minutes of mowing my fishing line got blocked, I had to turn it off and unlock it. When I turned it off, I saw that from the muffler side it was running down the scythe and there was such a black goo on the tank, I don't know what that means. Then, after cleaning this fluid and unblocking the line, the scythe refuses to fire: /
Could you check if it's not a problem for you, how many revolutions do you have this screw with a spring removed?

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... how many turns do you have this screw with a spring removed?

In mine - fully screwed in and unscrewed 3/4 of a turn.

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Should I maybe just leave the prop in a place like this between running like crazy and choking it?

It is not allowed to choke, just smoothly enter the revolutions and work evenly throughout the range of revolutions and at the same time not to smoke.

Check the tightness of the connection between the carburetor and muffler to the cylinder.

In the 3/4 position, unscrewed, it does not want to start at all, I set it to 1.5 turns, turned it on, I mowed for 15 minutes, it went out by itself and did not want to fire again, in addition, such black goo was flowing again as I mentioned in the previous post.

Could you tell me which one and how to regulate it?

I also had a problem with the fact that after some time it choked and finally went out, solving the problem turned out to be trivial. There is a tiny hole in the traffic jam that lets air into the tank, but it somehow clogged. There was then a vacuum in the fuel tank and the scythe could not pull fuel. It is enough to unscrew and close the tank every now and then and everything will be ok. I also opened this hole with the needle, but I think the needle was too big and now, when the tank is full, sometimes something will leak out of fuel.

Let me disagree with the honorable speaker. I would not touch the cork. The cork consists of three parts A, B, C. In the external elements A, C there are indeed 1.5 mm holes, but B is the proper part, where the working function is performed by a 2mm incision in the rubber material. Once I followed my friend Kamil's footsteps, but I had to replace the cap with a new one, because the fuel was leaking through the cap.
I find the comments of my colleague azxxc (# 2) valuable and helpful, but with a working carburetor. I tried this method (regulation of the mixture composition), but the effects were temporary and inconclusive. My observations about the carburetor as in the topic are as follows: the new carburetor does not require any adjustment after installation and works properly for a while until something hurts it, then no magic helps except buying a new one. I suppose the carburetor is hurt by storing fuel in the scythe's tank. Certainly, fresh fuel (not older than 3 months) is also important, as it loses more easily flammable fractions when it ages. At the moment I am already using the third carburetor. The cost of purchase is PLN 24. Falontech

The carb in this scythe is surprisingly complicated, the fuel diaphragm pump, channels and Micro Filterek, I warn you against mixing fuel in water containers, one drop will immobilize your engine. As for the aging of fuel, it is said that something happens with red oil after mixing with fuel after time, does not know it crystallizes? although the class of the oil is supposed to be the highest, probably even a synthetic oil. That is why many users use ordinary oil, even a mixer, this also applies to petrol chainsaws, and this information comes from a professional saw.