Why my blower want start and run?

Remove spark plug. If it's wet with fuel then likely it's flooded. Pinch off fuel line, dry out cylinder by pulling starter rope several times while spark plug removed. Dry and install spark plug.

If plug was dry or once you dryed cylinder and plug, set half throttle. Leave fuel line pinched off and spray a short 1 second burst of starter fluid directly into carburetor throat. Promptly pull starter rope up to three times.

If fire and runs for a second or two then spark is ok. If no fire, recheck for flooded cylinder. If not flooded, then no spark or low compression. Else release fuel line and attempt start. If no start or runs and stalls then likely it needs further carburetor work or bad fuel. Recheck for flooded cylinder.

Remove all fuel. Remove spark plug. Dry out the crankcase and cylinder by pulling the starter several times.

Reinstall spark plug. Remove air filter, hold throttle open and spray a short burst (~1sec) of starter fluid down throat of carburetor. Release throttle and promptly pull starter rope up to 5x.

If it fires and runs a few seconds then it is a fuel/carburetor problem.

If still no fire then more likely a spark or compression problem. Replace spark plug with new proper type and gap. Retry with starter fluid. If still no run then likely either a failed ignition module or poor compression/crankcase leak.

Remove air filter and spray a short burst of starting fluid directly into carburetor throat. Promptly start. If it runs for a few seconds and dies then no fuel from carburetor.

If it doesn't fire then, no spark, no compression, bad timing, or flooded.

There needs to be fuel, air, spark and compression. It may not start with starter fluid if it's already flooded. It may not start if a valve is stuck open.
You can take the sparkplug out and check to make sure it's not got excess fuel. Plug should be dry.

There is a special tool required as the screw heads are splined, base settings are 1 1/2 turns on both, it should run at this, the L screw will adjust fuel flow from idle to half throttle, the H screw will control the fuel to full rpm.
If the engine struggles to pick up, unscrew L screw a further 1/4 turn, or more until it picks up cleanly.
Now at full revs, gently screw the H screw in until engine sounds sweet, if it starts to die unscrew to achieve full revs.

These engines have a low oil sensor and if the oil is low, the engine will not have fire. So check the oil level first and make sure it is to the full mark.

Check the spark plug that it still has proper gap .028-.031 in and the proper spark plug BPR6ES (NGK) or W20EPR-U (ND). While you have the spark plug out let's see that it is firing, reattach the plug wire to the spark plug and make sure the spark plug is in contact of a bare metal surface for a ground, the crank the engine over watching for spark in the gap of the spark plug. It would be best to check this in a low light area. Keep in mind that checking for spark this way and there is spark but when the spark plug is installed and there is compression the spark may not jump the gap as it should. If no spark with the plug out check the spark plug wire for cuts or tears and it none seen get a new spark plug. If there is spark with the spark plug out reinstall the spark plug. If the engine hasn't been started for some time drain the gas out of the fuel tank and carburetor. There could be water in the fuel also but to check if there is fire get a can of starting fluid. Drain the carburetor anyway at this point because if there is water in the fuel the next step may not fire the engine because of the water. Take the air filter out and give the opening of the carburetor a short spray of starting fluid. Try to start the engine, if it doesn't start or fire with the starting fluid there is something wrong in the ignition system. The Digital CDI Ignition Coil could be bad but before buying a new one you need to check the shear key of the flywheel to the crankshaft to make sure it is in good shape. You will need to remove the flywheel for this. If the key is in very good shape, then it is the coil.

If the engine fires on the starting fluid then you have water in the fuel or the fuel is not getting into the engine as it should from the carburetor. The carburetor needs to be cleaned.

Dump out the old gas and put in new.Try a spray of starting fluid into the carb. If it will not fire on the starting fluid there is somthing wrong in the ignition system. Pull out the spark plug and clean it with a wire brush. If it still won't fire the points and condensor need to be replaced.
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Try a spray of starting fluid into the carb. If it fires you know you have good spark. If it did not fire replace your spark plug. If it still won't fire point and condensor need to be replaced. If it did fire spray the starting fluid in the carb a few more times to pull the old fuel through the fuel line til the new gas gets through the carb and then it should run. Some machines have a fuel shut off valve make sure it is open.

check gas tank with light is there dirt in tank? did you change fuel filter? is there spark at the spark plug? try a 2 second spurt of starting fluid in carburetor and crank does it fire?if it does then you most likely need to clean carburetor with carburetor cleaning spray, flush fuel lines with spray and swap fuel filter.

Main cause of small gasoline engine failure is carburetor clogged. Try spraying carburetor cleaner into carburetor and intake. Check if unit has air cleaner. If engine starts briefly with cleaner then carburetor needs manual cleaning. Carburetor removal and overhaul.