Don't know what position the valve should be in. It is on a 50cc and it is a screw type

manual page 36 is your trouble shooting guide sounds like still a fuel delivery problem -filter-lines -valve-tank etc ------------https://www.manualslib.com/manual/1090554/Taotao-Atm50-A1.html

Since your Husqvarna is a two stroke engine there is almost certainly a reed valve between the carburetor and the cylinder.

When your piston is at top dead center - and you roll the crank shaft in the forward direction - the next valve that opens determines what stroke it is on. If the exhaust valve opens - it is on the that stroke. Only AFTER you reach TDC.

!980 gS750l HAS A SCREW HEAD TYPE PETCOCK. IT LOOKS LIKE THE LEVEL IS MISSING BUT THAT IS THE STOCK PIECE. TWO SCREWS HOLD THE PETCOCK TO THE TANK. REMOVE THOSE AND THE PETCOCK BASICALLY FALLS OFF. YOUR NEW ONE SHOUILD HAVE AT LEAST THE SAME BASE WITH THE SAME DISTANCE BETWEEN THE SCREW HOLES.

On your mixing valve, Your hot and cold water should hook to the valve at 9:00 and3:00 positions. You should have two ears at 12:00 and 6:00 positions which are used to screw the faceplate on. If you don't see these ears, the hole that the valve is in may not be big enough for you to see them. If it is tile, they may be covered with tile. If it is fiberglass, you would usually would have an oblong hole, longer at top and bottom, to see ears. If it is fiberglass, you may want to drill through where screws go, and through bolt your valve so it is tight. The hole in tile and/or concrete should be oblong so you can see screw holes.

Don't know what type of gas appliance your are working on, but if you installed a thermocouple, the biggest mistake made is screwing it into the control valve to tightly. When installing a thermocouple, it should be tightened only finger tight and with an appropriately sized wrench turned only a quarter turn more. Over tightening it will casue the gas control valve to lockup and gas can't reach the pilot.

Also, after reinstalling the thermocouple, be sure the control knob is really in the Pilot position. You can tell if it is, as knob will fully depress and bottom out,. And you'll feel more than spring pressure pushing back at you.

Hope this helped you to troubleshoot and solve the problem.

there are to eletrical components next to one another. The throttle position sensor and the idle control vavle. They are right where the air supply housing goes into the metal part of the air intake system. Right at the firewall the air intake line, a big rubber hose, attaches to the metal trhottle body. The bottom of the two is the idle control valve. It has an oblong electrical connection and uses a small "torgues" type male wrench to get the two screws out. Torgues is the star shaped screw, rather than a hex head of phillips head type screw.

The lower of the 2 screws is the fuel/ air mixture- the upper screw is the idle adjust screw

If you know what the throttle valve is then you can replace the sensor, it is over 1 end of the throttle valve shaft , it is held in place by 2 screws, they may be Torx style screws, not sure on your model.