Honda CR125R 2006 Owner's Manual page 56

Cylinder System
Connecting Rod Inspection
1. Temporarily remove the shop towel.
2. Install the small end bearing (1) and piston
pin (2) in the connecting rod small end and
check for excessive play while holding the
connecting rod.
If it feels loose, replace the piston pin and
small end bearing.
(1)
(1) small end bearing (2) piston pin
3. Place the shop towel back in the crankcase.
Cylinder Head Inspection
Check the cylinder head (1) for warpage in
diagonal directions with a straight edge (2) and a
feeler gauge (3).
Service Limit: 0.002 in (0.05 mm)
(3)
(1) cylinder head (3) feeler gauge
(2) straight edge
52
Servicing Your Honda
Piston Installation
1. Clean the piston ring groove.
2. Lubricate the piston ring and piston ring
groove with clean 2-stroke oil.
3. Install the piston ring on the piston with the
marks facing up.
Locate the piston ring end gap on the pin in
the ring groove.
4. Lubricate the small end bearing and piston pin
(1) with clean 2-stroke oil.
5. Install the connecting rod small end bearing,
(2)
piston and piston pin.
Install the piston with the "IN" mark (2)
facing the intake side.
If the "IN" mark is not found on the piston,
install the piston with the hole (3) facing the
intake side.
6. Install new piston pin clips (4) (Never reuse
old clips.)
Take care so that the clips do not fall into the
crankcase.
Do not align the piston pin clip end gap with
the piston cut-out.
(2)
(1) piston pin
(2) "IN" mark
(1)
Cylinder Installation
1. Clean off any gasket material from the gasket
surface of the crankcase, being careful not to
let any material fall into the crankcase.
Be careful not to remove any metal from the
gasket surface.
2. Remove the shop towel. Do not let any gasket
debris fall into the crankcase.
3. Place the new cylinder base gasket (1) and
dowel pins (2) on the crankcase.
(1) cylinder base gasket
(2)
4. Lubricate the piston and ring with 2-stroke
(3)
NOTICE
(1)
Do not rotate the cylinder, since this may cause
(4)
the piston ring to snag a cylinder port and break.
(3) hole
(4) piston pin clip
(2)
(1)
(2) dowel pin
oil. Align the ring end gap with the piston
ring pin (3) in the ring land and slip the
cylinder (4) over the piston while
compressing the piston ring.