16 Tooth Sprocket + Needle Shim Combo = spark plug fouler?

[Canuck]

In reference too... (16 Tooth Sprocket + Needle Shim Combo)

Hey I was just curious if anyone else who has these 2 specific mods done to their GZ.

And if so...did you find that it seems to go through the spark plug quicker and if there is a rational explanation behind all this?

Also with these two mods should I also adjust the lower screw on the GZ's Carburator( some owners have a brass plug preventing direct access to this adjustment)
In addition to this once access is gained should you increase the numbers of turns or decrease and by how much ?

Thanks everyone