After removing the riser, there is less meat in the neck of the riser.
The shape and size of riser neck are unreasonable or the slot position is wrong
Plan improvement measures:
A. Improve riser neck shape
B. Reducing the cross-sectional area of riser neck
C. Add a slot on the riser neck (generally 90 degree slot), so that the casting and riser are disconnected from the slotted part to avoid coupling
D. It is suggested to improve the method of removing riser, such as using saw riser instead