With all respect Joe, you are wasting time and money with your excessive sparkplug replacements. Unleaded fuel keeps plugs clean (really clean) in a car nowadays for in excess of 100,000 miles, plus or minus. Scooter and motorcycle engines are no different if in good shape.
I'm on my 76th scoot/ motorcycle and I haven't had a sparkplug fail in any of them. Even on my 2 stroke, track and desert competition bikes it was a very rare occurrence.
Years ago, the bike/ scoot mfg's wanted to replace the sparkplugs during the first service which was just additional profit for them. If they insisted, then I insisted that they give me the plug (S) that they removed.
A fuel additive like Techron, Seafoam, Lucas etc, used occasionally, keeps the plugs even cleaner and cleans the valve seats, the tops of the pistons, the combustion chamber and of course the entire fuel system.
Sam:)