PGO Bug Rider BR-250, Service Manual

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5
. CYLINDER/PISTON
5
BR & M2 250 ENGINE
Service Limit : 16.96mm replace if below
Measure the piston O.D.
Service Limit : 72.60mm replace if below
Measure the piston-to-piston pin clearance.
Service Limit : 0.02mm replace if over
CYLINDER INSPECTION
Inspect the cylinder bore for wear or damage.
Measure the cylinder I.D. at three levels of top,
middle and bottom at 90
°
to the piston pin (in
both X and Y directions).
Service Limit : 72.80mm repair or replace if
Over
Measure the cylinder-to-piston clearance.
Service Limit : 0.1mm repair or replace if
Over
The true roundness is the difference between the
values measured in X and Y directions. The
cylindricity (difference between the values
measured at the three levels) is subject to the
maximum value calculated.
Service Limits :
True Roundness : 0.09mm repair or replace
if over
Cylindricity : 0.09mm repair or replace if over
Inspect the top of the cylinder for warpage.
•
Take measurement at 9mm from the
bottom and 90
°
to the piston pin hole.
＊
Middle
Bottom
Top