Romet home edition snow thrower - No power, rough engine running

Hello

About 3 years ago I bought a Romet home edition 2 snow thrower. In the first year it only worked for a few hours. In the second and third, hardly any. When I wanted to do a test run in the summer, it was impossible to start it for the treasures of the world. So I unscrewed the carburetor and cleaned the nozzles and all available chambers. By the way, I removed a lot of nasty (greenish) deposits, they looked like oxidized copper. I also took off the fuel tank. I cleaned it and poured fresh fuel. After putting everything together, the snow thrower fired after a few attempts but the work was not very stable. After a dozen or so minutes the engine worked quite well. So I thought - it's OK.
Until today, when quite a lot of snow fell, I decided to start the machine. After several attempts to start it, it fired. She worked the choke for a few minutes, then the choke half. when I took off the choke completely, the engine stopped. And so I fired for 15 minutes and tried to move - with a poor effect, unfortunately. After many attempts and strong manual gasification (I pulled the rods by hand), it started a little, but I estimate that it was about 50% of the power and the engine work was very uneven - there were often shots. I hardly cleared the driveway and the engine went out immediately with a light load.
I estimate that the engine works perfectly at idle, after increasing the revolutions it works well, but when the engine is loaded with work, there is no power. I also unscrewed the candle, it was OK but I cleaned it - no changes
I already have no ideas what might be wrong with the engine, so please help, maybe someone had a similar problem.
The engine of the snow blower is OHV LONCIN 196 CC 6.5 HP. (at least that's what they wrote there).

Exhaust shots and a drop in power under load may indicate an ignition problem. I don't know how it is constructed in this equipment, but it is worth taking a look at.

The shots were exhaled, or so it was audible. The machine was fired for 5-10 minutes at least twice a year.

Thanks, I'll test tomorrow

Today I finally found some time to rummage around the machine. With momentum, I took off the entire carburetor and once again blew through all the nozzles found (2 pcs - one as shown in the picture and the other under the cover of the float chamber), I also unscrewed the fuel mixture adjusting screw and blew this hole. I checked the patency of the fuel lines and the fuel tap. Then I installed the carburetor and what ??? And nothing's unchanged !!! I only noticed that the situation with the power and acceleration of the engine is temporarily saved by the constant pumping of the fuel start button.
I took off the carburetor again, then the float chamber because I think maybe the fuel level is too low in the chamber and you need to raise it. I was staring at this needle valve for half an hour, and unfortunately I didn't think of any way to regulate it. There is a plastic float mounted on an axle. A valve on a spring is attached to the float and nothing else. No intermediate plate to adjust. Below are pictures of what it looks like.

These are not my photos, but basically it looks like this

Added after 1 [minutes]:

and this

Hmmm. Honestly speaking, they looked so flat, as if they were squashed, that is, they were not completely round around their circumference.

Unfortunately, replacing the O-rings did not help. I visited the gardening machinery service and there the service technician stated that these carburetors sometimes clog up so badly and even ultrasonic cleaning does not help, it is best to replace the entire carburetor. I did a little research on the internet and found similar carburetors but not the same. My carburetor has a decanter and a hose connector (for the suction pump).
And now I do not know if there must be this decanter and whether this engine requires a suction pump or a choke lever is enough because I have not found the carburetor for the pump on sale ???

And the fuel flows freely from the sandbar with the fuel tank cap screwed on? Maybe it's getting air.
If not the tank, carefully calibrate both nozzles with a heavy wire, only clean the one with the O-rings with a needle, there is a hole in the brass part, and slightly enlarge this nozzle in the float chamber, but only slightly. Of course, if you plan on buying a new carburetor

The matter is settled. A radical but effective move - replacing the carburetor. A new replacement with a shipment of PLN 65. The snow thrower works like new. Carburetor so dirty (internal channels - not nozzles) that flushing several times has no effect. Sometimes time is more valuable