Engine running erratically - hunting & stalling.will only run with choke & stalls when throttle opened. emptied fuel tank and checked filter gauze, put in fresh petrol but no improvement.

Sounds like there is a blockage in the fuel line that lets gas through for a short period of time, then becomes very low and the engine stalls. Look for dirt in the lines and clean out.

Check your fuel filter is clear, although as its only 2 years old shouldn't really be a problem but that depends on how good the fuel is. Also check the fuel tank itself is "breathing". Run the engine for a while and open the fuel flap and listen. Do you hear a sound of air being pulled into the tank. If so it isn't breathing and the breather needs clearing (I took my fuel cap to pieces and cleaned before replacing). If it stalls out after idling for a few minutes, try idling with the fuel cap open (be careful though) to see if it runs fine.

maybe need to put a full kit through carb. and replace few worn parts ie. float needle and seat. throttle needle and seat etc

Check fuel tank or cap vent to be sure it is not plugged.

I had the same problem in my craftsman, the problem was in the choke. the spring was broken and it runs fine now after replacing the spring.

Check the steel fuel line under the intake manifold
had one that was almost completely clogged shut with ****
took a month of hunting but found this to be the problem

Most likely there's a problem with fuel supply - choking cuts air supply optimizing the air/fuel mix. Most common solution is to check and clean the carburetor.

If there's a tiny fuel filter in the fuel line between tank and carburetor check it on excessive pollution. Replace it when necessary.

When opening the blower for carburetor cleaning - also check the airfilter and replace when dirty.

If never opened the blower - take pictures with a digital camera at each step. The pictures can help with assembly after cleaning.

try testing/replacing the coil. if it stalles after the car warms up that gives the coild time to over heat and die.

When the gun trigger is pulled, the back-pressure holding back the engine is reduced and the engine accelerates.

Your engine is dying when it should accelerate.

Good news is you have spark and combustion and fuel and the engine runs.

1) Check the exhaust port for build-up of carbon or dirt >>> the hot exhaust gas has to fly out of the exhaust port and if the port is clogged, then the engine stalls

2) Check the amount of fuel getting through to the carburetor >>> pull off the rubber hose entering carburetor from the gas tank >>> does gas run out freely? If gas does not run freely, then take apart your gas filter located just below gas tank

3) Remove air filter and see if problem continues. A dirty air filter can cause engine to stall since combustion requires oxygen coming through the filter. Replace the air filter.

4) Mess with the choke lever and see if you can find a setting where the engine works >>> our old power washer would never run when lever was moved to full throttle >>> we just left the choke lever at half throttle and the engine was happy

5) If above fixes don't fix the problem >>> the final suspect seems to be the carburetor >>> try some gun-out >>> maybe a trip to small-engine repair shop is required.

I would have the TPS (throttle position sensor} checked. Its purpose is to provide input to the engine controller in relationship to your movement of the gas pedal. If the engine controller is not getting the proper signal from the TPS the engine will run erratically and stall.
Good luck.