55CC的說明書有寫
Since the carburetor points downward when the engine is
installed inverted, it becomes more difficult for the fuel to
reach the carburetor on priming (choking).
Therefore a heavier priming will be required.
所以需重調化油器油針 且是退低速油針是合理的
呵~~我果然能調出一口的好引擎 光說不練