I have never needed to close that hole on any
engine . I always believed it was there to allow enough airflow to carry the fuel into the engine , no airflow no fuel movement.
+1 though I did close the hole on one engine that was especially reluctant to pull fuel. I later drilled a small hole in the solder used to close the hole as it was prone to over choking otherwise.
Last edited by Truckracer; 04-07-2016 at 04:56 PM.