Vespa two cycle decarbonization

[railfancwb]

Flipping through a recently acquired Haynes manual for the P/PX two cycle scooters, I noticed that it recommended decarbonization of the engine every 2500 miles.

Basically this was removing the plug, exhaust system, and head (plus things in the way of those) and scraping carbon from the head cavity, the piston top, the exhaust interface, and cleaning/replacing the plug.

Has this always been the recommendation?

My fifty year old memories of working on my Vespa/Allstate do not include such a routine maintenance activity. If I had the engine apart for other reasons I probably scraped the carbon away.

If this maintenance activity has not been done over a considerable number of miles, what is the most probably result?

Thanks.