Scooterotica

Recently bought my first Lambretta, so forgive me if I sound like a retard. I've got a standard DL150, and occasionally, when the engine is warm, the tick over increases, as if something is sticking. I've sprayed WD40 on the various external moving parts/springs, and it seems that the throttle is closing properly. Any ideas what to look at next?

Sounds maybe like an air leak mate . If any of the top end gaskets leak a little when warm tick over does increase and could lead you to believe its the carb

Thanks Nellyboyo. I'll have a look on the weekend and see what I find.