[Porky]

Your float bowl float may be stuck, not rising enough to shut off fuel when the bowl is full.
Simple fix is to remove the Carb and fix the problem or if you don't want to attempt it, take the carb to a Vespa/ Piaggo or Aprila dealership and have their service dept do it, that way if it needs parts, they can order them and fix the problem.

It is a very simple fix

Sam

 

[Porky]

很抱歉，您甚至不知道化油器在哪里。也许要调整空转止动螺丝-如果可以找到的话。
Hěn bàoqiàn, nín shènzhì bù zhīdào huà yóu qì zài nǎlǐ. Yěxǔ yào tiáozhěng kōngzhuǎn zhǐ dòng luósī-rúguǒ kěyǐ zhǎodào dehuà.

Samuel

 

[Porky]

Me too
Sam