Andre , all engines 2 cycle or 4 cycle can be effected by atmospheric conditions and age . Engines will run differently during dry sunny days or during cloudy damp days . That is why computerized ignition controls systems have been developed . New chainsaws and generator sets now utilize computerized fuel management systems , that monitor fuel / air ratio,s , barometric pressure (air density) , etc . Apparently your friends blower is now not requiring full choke during a cold start procedure . You did not state whether the engine is 2 or 4 stroke ? Either way , the most common cause of this condition normally after a few yrs use , is either a dirty air filter or more often in 4 strokes is a fouled ( carbon ) often a combination , since a dirty air filter will cause excess fuel within air ratio and cause carbon within the engine head and valve train . A secondary cause is the actual carburetor air / fuel circuits can become fouled and further the adjustment screw needles them selves can become fouled or worn allowing more fuel or less air or visa virsa ! lol. You personally have witnessed both fuel starved and now a fuel rich engine condition . Unfortunately numerous grass trimmers , blowers , lawnmowers etc still require a vigilant eye and ear to diagnosis such conditions since they do not have computerized fuel delivery systems . I would advise again to have him check his air filter and spark plug condition ( black , oily ) both will affect this condition , clean or replace . Also add a ounce of your Startron to his fresh fuel and run a tank through the blower to ensure the fuel system is also clean from any residual stabil !

Well I had a spare filter from a while back and happened to have a new plug so I swapped out both. It did start right up with the choke in the middle position. I guess he will have to try it a few more times and see if that made a difference. You can see the condition of the filter in the picture ..it looked a little yellow and underneath it seemed a little wet. Not sure what that means but it seems to be running okay .... whether it only will start full choke... that's something he will have to test over the next few days .

2 stroke or 4 stroke ? Plug looks ok , a little darker than optimium , filter not overly dirty , although the yellow staining appears as flooding condition at some point . It appears as a 4 stroke since no oil staining of filter along with the gas . As I said a little startron added to fresh fuel will ensure all is well internally with carburation and valve train , you can enlighten him of the benefits Andre !