general information - Martin Nez

3-36 ENGINE• If the seat width W measured exceeds the standard value orseat width is not uniform, reface the seat using the seat cutter. Valve seat width W:Standard: 0.9 – 1.1 mmIf the valve seat is out of specification, re-cut the seat.VALVE SEAT SERVICING• The valve seats 1 for both the intake valve 2 and exhaustvalve 3 are machined to four different angles. The seat contactsurface is cut at 45°.60˚30˚45˚60˚15˚45˚INTAKEEXHAUSTSeat angle 30°, 45°, 60° 15°, 45°, 60°Seat width 0.9 – 1.1 mm 0.9 – 1.1 mmValve diameter 27.2 mm 22 mmValve guide I.D. 4.000 – 4.012 mm 4.000 – 4.012 mm* The valve seat contact area must be inspected aftereach cut.* Do not use lapping compound after the final cut ismade. The finished valve seat should have a velvetysmooth finish but not a highly polished or shiny finish.This will provide a soft surface for the final seatingof the valve which will occur during the first fewseconds of engine operation.NOTE:After servicing the valve seats, be sure to check the valve clearanceafter the cylinder head has been reinstalled. (2-7)