Crankshaft Assembly; Inspection And Repairing; Cylinder Head - Yamaha LB50IIAC Service Manual

Crankshaft assembly
Remove crankshaft assembly with the
crankcase separating tool.
INSPECTION AND REPAIRING
Cylinder head
1. Remove spark plug.
2. Using a rounded scraper, remove carbon
deposits from combustion chamber.
Take care to avoid damaging the spark
plug threads. Do not use a sharp
instrument; avoid scratching aluminium.
3. Place on a surface plate. There should
be no warpage. Correct by re-surfacing
as follows:
Place 400 - 600 grit wet sandpaper
on surface plate and re-surface head
using a figure-eight sanding pattern.
Rotate head several times to avoid
removing too much material from one
side.
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