Welcome Kymco Owners!
According to that article I should also get a high energy ignition coil/wire/plug cap to improve starting, acceleration, and fuel mileage.
That is the very first thing you should do. I see it as a "given". You have to have at least 35,000 volts to get complete combustion. Most if not all OEM 50cc coils are 6,000v. Get one of the orange "performance" coils on ebay, or partsforscooters. You will get better performance /mileage. I am setting up an MSD battery driven CDI, and an Accel coil made for a 2012 jeep. That will be a stable 60,000 volts from start up to 16,000 rpm. Fire is the trigger.
"As far as i was told, the standart kymco coil was 16000 volts." Forgot the one (1) 16,000v. Still half the power, and MUCH weaker spark under compression. You want the spark to jump at LEAST 1/4" with the plug outside the engine.
One quarter inch. http://www.toolfetch.com/Category/Automotive/Spark_Testers/THE404.htm This is the tester I use to trouble shoot. If I cannot get a 1/4" gap to jump I KNOW it will be an Ign related running problem.
Any Good coil. Compression increases the air resistance inside the Cyl. I don't know the formula but I do know you have to jump 1/4" to get spark under compression. Even erratic spark at 1/4" will not fire in the cylinder under compression. At 60,000 volts you don't even need an electrode. It will jump to ground. http://compare.ebay.com/like/390407578892?var=lv<yp=AllFixedPriceItemTypes&var=sbar That is the OEM plug for a 60,000 volt marine 2t engine (out board)
Nobody NEEDS iridium . It's more a question of do you want to pay the extra couple of dollars for the improved performance , easier starting , and longevity .