Valve Seat Replacement

When valve seat is removed, replace with oversized [0.5 mm (0.020 in)] valve seat.

1. Bore out old seat until it collapses. Boring should not continue beyond the bottom face of the seat recess in cylinder head. Set the machine depth stop to ensure this. Refer to [SERVICE DATA AND SPECIFICATIONS ].
   CAUTION: Prevent to scratch cylinder head by excessive boring.
2. Ream cylinder head recess diameter for service valve seat.
   Fig 1: Reaming Cylinder Head Recess Diameter For Service Valve Seat

   Courtesy of SUZUKI OF AMERICA CORP.

   Oversize [0.5 mm (0.020 in)] 

   Intake: 38.500 - 38.516 mm (1.5157 - 1.5164 in) 

   Exhaust: 32.700 - 32.716 mm (1.2874 - 1.2880 in) 

   • Be sure to ream in circles concentric to valve guide center. This will enable valve to fit correctly.
3. Heat cylinder head to 110° to 130 °C (230° to 266 °F) by soaking in heated oil.
   Fig 2: Heating Cylinder Head

   Courtesy of SUZUKI OF AMERICA CORP.
4. Provide valve seats cooled well with dry ice. Force fit valve seat into cylinder head.
   WARNING:

   • Cylinder head contains heat. When working, wear protective equipment to avoid getting burned.
   CAUTION:

   • Avoid directly touching cold valve seats.
5. Finish seat to the specified dimensions using suitable tool. Refer to [SERVICE DATA AND SPECIFICATIONS ].
   Fig 3: Fitting Valve Seat Into Cylinder Head

   Courtesy of SUZUKI OF AMERICA CORP.
   CAUTION: When using valve seat cutter, firmly grip cutter handle with both hands. Then, press on the contacting surface all around the circumference to cut in a single drive. Improper pressure on with cutter or cutting many different times may result in staged valve seat.
6. Using compound, grind to adjust valve fitting.
7. Check again for normal contact.