TOHATSU BFT115A Service Manual page 448

CYLINDER HEAD
After cutting the seat, apply lapping compound to the
valve face and lap the valve using a commercially
available valve lapper (1).
• Excessive lapping pressure may deform or damage
the seat.
• Change the angle of lapping tool frequently to
prevent uneven seat wear.
• Lapping compound can cause damage if it enters
between the valve stem and guide.
After lapping, wash any residual compound off the
cylinder head and valve.
Recheck the seat contact (page 14-46) after lapping.
14-56
(1)