We have been fighting the 'junk' fuel issue since the '90s in the bike world. Could used to loosen spark plugs to lower compression and spark plugs would clean out themselves simply by cranking the engine over. Remove them and blow them out with compressed air would work also. Somewhere in the late 90's on, almost have to beed blast the plug tips to clean them out. Times through the 80's when a bike carb needed to be cleaned, open the bowl up and would find a green coating of stale gas inside. Now days there is a white color film, shale or powder clogging the carb. First thing to clog is the pilot jets causing no start. Most people choke the engine after it will not start and foul coat the spark plugs. More and more as years pass, cleaning the pilot jets with carb cleaner and compressed air will not do the trick anymore. I'm constantly using index drill bits on pilot jets to unclog them. The best thing out there to add to fuel if the unit is to set for a while is Sea Foam. pour the spec amount into the tank then let the unit run for about 15 minutes to make sure it is distributed through the fuel system and coats the inside of the float bowl... drain the bowls afterwards to ensure no stale gas mix will foul plugs when restarted. Only draining the float bowls with no fuel treatment run through the system will only accelerate the white shale or powder to accumulate, at times to the point it will eat into and distort components inside the carb
