Yamaha 2003 TZR50, Service Manual

Page: 94 / 251

ENG
INSPECTION AND REPAIR
4-15
Measuring warping and steps for sanding
the surface:
• Put a straightedge and a thickness gauge
on the cylinder head
• Measure the warpage
Outside specifications Sand / Replace
• Place nº 400~600 wet sandpaper on the
surface and sand this down in a figure
eight shape.
NOTE
Turn the cylinder head round several times
so as not to take too much material off only
one side.
PISTON
1. Eliminate:
• Any carbon deposited (on the piston and
the ring slots)
2. Eliminate:
• Scratches and deposits found (on the
wall of the piston)
• Use nº 600~800 water sandpaper
NOTE:
Sand this in a cross shape and do not sand
excessively.
3. Inspect:
• The piston wall
• Wear / Scratching / damaged
Replace
Maximum cylinder head warpage:
0.03 mm