Answer :
Final answer:
Excessive valve stem height is commonly fixed by grinding material from the valve tip to restore proper valve train geometry and operation. Other methods listed do not address the issue of stem height.
Explanation:
Excessive valve stem height is usually corrected by grinding material from the valve tip. This is because the valve stem height impacts the relationship between the valve and the rocker arm or lifter. When a valve has been ground to correct the seating surface, the stem becomes effectively longer and can interfere with the proper geometry of the valve train.
The process involves removing material from the end of the valve stem to restore the correct height. This allows for proper clearance and optimal operation of the valves and associated components. Other options such as replacing the valve spring, adjusting the rocker arm, or changing the valve seat do not correct excessive valve stem height.
