gbvona
Member
The pistons in my HIF6 carbs (AUD623) have a rectangular slot milled in the bottom of the piston, about 2 mm deep, 4 mm wide and parallel to the airflow. It goes all the way across the piston. However, there is a steel insert in the middle of the piston (into which the needle bush is fit) the bottom of which is flush with the bottom of the piston, interrupting said slot in its middle.
The WS manual says to insert the needle guide (bushing) into the piston until its bottom face is flush with the bottom of the slot in the piston. This would set it into the steel insert about 2 mm. I also have an SU leaflet on the HIF6 that says to insert the needle so as to have the end of the straight shank on the needle flush with the bottom of the piston. Since the straight shank of the needle sticks out of the needle guide about 2 mm, this spec would be more or less consistent with what is in the WS manual. Just checking to make sure that interpretation is correct.
And that being said, what is the slot for, since the steel insert blocks it halfway across the piston??
gbvona
PS Was privileged to hit the Goodwood Revival Friday and Saturday. Y'all sure know how to throw a party.
The WS manual says to insert the needle guide (bushing) into the piston until its bottom face is flush with the bottom of the slot in the piston. This would set it into the steel insert about 2 mm. I also have an SU leaflet on the HIF6 that says to insert the needle so as to have the end of the straight shank on the needle flush with the bottom of the piston. Since the straight shank of the needle sticks out of the needle guide about 2 mm, this spec would be more or less consistent with what is in the WS manual. Just checking to make sure that interpretation is correct.
And that being said, what is the slot for, since the steel insert blocks it halfway across the piston??
gbvona
PS Was privileged to hit the Goodwood Revival Friday and Saturday. Y'all sure know how to throw a party.