These carbs are not like lawnmower carbs. Just delivering air and fuel is not enough for it to start up and stay running. it needs to be taken apart and cleaned meticulously. The very small orings on the needles are also prone to dry rotting and cracking when sitting. Cleaning and rebuilding the carb will greatly increase the chances of it starting. Also do not spray carb cleaner in the carb unless every o ring has been removed, it will make them swell and ruin them.
You can also check quick to make sure the plug is actually heating up. Take the plug out and just leave the wire connected. Then just hold the threads of the plug somewhere on the engine and spin the engine over. The plug should glow bright orange hot. If it doesnt youve found your problem