Every on has a different opinion on what to do at the end of the day we don’t recommend draining the fuel out of the carb when being stored for short periods. over the years i have seen carbs that have been drained regularly and after a while there can be corrosion and foreign material found in the bowl of the carb when you refill next time the crap in the bowl gets mixed with the fresh fuel & ends up going through the carb & can block jets & internal passages.
Oil Changes should be done frequently the more often you change your oil the better your engine will be, Use a quality oil designed for Air Cooled engines start out with 450ml of oil depending on the angle of the engine some engines only need 420ml & some people run up to 600ml.
The Valve springs & rockers in your clone engine were originally designed to be run at 3600 RPM. Many people remove the governor & run the Clone engines far beyond the 3600 rpm range. There are many negatives to this the main one being safety. Valve lash or rocker clearance should be checked before your new engine is fired up. A Recommended setting with the stock cam for both the inlet and exhaust when set cold is .003 to .004 thou. As the engine gets hot the rocker clearance gets bigger if the rocker clearance is to large you will find the engine will drop off in performance and the rocker arm can fall of the valve brake the rocker, bend a rocker stud or smash the valve or retainer. If rocker clearance is set to tight you run the chance of the rocker riding the valve & holding the valve of the seat & also losing power.
The ignition system needs to be set so an air gap is created between the coil & the magnet that is in the flywheel.oon standard type hot coils a gap of .015 thou seems to work fine these can be set & checked with feeler gauges
The best fuel to run in your engine is a premium type fuel octane boosters & fuels with a rating over 100 are not suitable due to the compression ratio of your engine.The average clone engine has a compression ratio around 8:50 to 1