Replacing Valve Guide - Benelli TNT125 Maintenance Manual

●Check the valve guide and remove the carbon deposits
in the valve guide with a reamer before check.
Note
Rotate the reamer clockwise and do not rotate
the reamer counterclockwise.
●Allowable limit: Measure the inner diameter of valve
guide [a]. Allowable limit:
○Intake valve：4.55mm，
○Exhaust valve：4.54mm。
●Allowable limit of clearance between valve and valve
guide:
○Intake valve：0.1mm。
○Exhaust valve：0.1mm。

Replacing Valve Guide

Note:
If the clearance between valve and valve guide
exceeds the limit, replace the valve guide. After the
valve guide is replaced, the valve seat ring surface
must be finished.
●Put the valve guide in the freezing cavity of
refrigerator to cool it for an hour.
●Use the electric furnace or oven to heat the cylinder
head to 100-150℃.
Valve reamer
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