Yamaha F4 Service Manual

Also see for F4: Owner's manual Owner's manual Brochure & specs Owner's manual Owner's manual

Contents

EROCKER ARM AND VALVESPOWRA B CValve seat refacingNOTE:After refacing the valve seat or replacingthe valve and valve guide, lap the valveseat and valve face.cCTo prevent chatter marks, turn the valveseat cutter with an even, downward pres-sure (4 ~ 5 kg).9Refer to the following chart to deter-mine the appropriate valve seat cut-ter.5-19Valve seat cutter set:YM-91043-C/90890-06803Valve seat lapper:N.A./90890-06805Valve seat area Valve cutterA 0°B 45°C 60°Valve seat cutting guidelines1 The valve seat is centred on the valve face,but is too wide.Valve seat cutter set Desired resultFirst:Use 0° cutter To reduce thelightly Second: valve seat width.60° cutter12 The valve seat is in the middle of the valveface, but is too narrow.Valve seat cutter set Desired resultTo achieve aUse 45° cutter uniform valveseat width.2