Honda XR80R Service Manual page 120

CYLINDER IPISTON
Unit· m m (in)
ITE M
STANDARD SERVICE LI MI T
Piston ,
XR80R
Piston mark di rection "EX' mark facing Toward the exhaust sid&
- -
piston rings,
Piston 0.0. 47.465 - 47.490 (1.8686 - 1,8697) 47.40 (1.866)
piston pin
P i ~lon 0.0. measurement point 7 mm (0 ,3 in) from nott()m of skirt
Pisto l1 pin bore 1.0 . 13,002 - 13.00810.5119 - 0.51211 13.04 (0.5 131
PiSton pin 0.0.
12,994 - 13.000 (0.5 11 6 - 0 .5 118) 12,96 (0,510)
Piston.to·piston pi n clearance 0.002 - 0.01 4 (0,0001 - 0.0006) 0 ,020 (0.0008)
Piston ring·\o·
TOO '98 - '99
0.015 - 0.050 (0.0006 - 0,0020)
0.1010.004)
ring
groove
Alter '99 0.015 - 0.045 (0.0006 - 0 ,0018) 0.10 (0,00 4)
ele~rance
"""d
'98 - '99
0.Q15 - 0.045 (0.0006 - 0.0018)
010 (0.004)
After '99 0.015 0.045 (0.0006 - 0.0018)
010 (0,004)
Piston ri ng
Top
'98 - '99 0.15 - 0,35 (0.006 - O.ot 4)
0 ,510.02)
en d gap
After '99 0. '
0.25 (0 ,004 - 0.0 10) 04 (0.021
SecoJ\d '98- '99 0.15 - 0.35 (0 ,006 - 0,(14) 0.5 (0.02)
After '99 0,1 - 0.25 iO.004 - 0.010) 0. 4 10.02)
OiHSid~ '98- '99 0,3 - 0.9 (0.01 - 0.04) 1.110.04)
rai l)
Aft8f
'~
0.2 - 0.7 /0.01 - 0.03) 0.9 (0.04)
Cylinder-to·p is\on clea ra nce XR 100R
0.01 - 0 .04 (0.0004 - 0,00161 0. 10 (0.00 4)
XRBOA
1).1)1 - 0.04 (0.0004 - 0,0016)
0.1010.004)
Con necti l1 g rod sma ll end
XR100A
14,012 _ 14.030 (0.5517 - 0.55231
14.05 (0,553)
1.0.
XR80R
13.016 - 13.034 (0.5124 - 0.5131)
13.0 4 (0.513)
Connect ing rod·to -piston XR100R
0.1)16 - 0.0 40 (0.0006
0 ,0016) 0.03 (0.001)
pin c lea rance
XR80R
0.016 - 0.040 (0.0006 - 0,0016) 0.Q3 (0.001)
TOROUE VALUE
Cam chain tensione r adjusting bo lt lock nu t 12 N ' m (1.2
~ gf' m,
9 lbfoft)
TROUBLESHOOTING
- If th e perfo rmance is poor al low speeds, check lo r while smohe in the crankcase breat her lUbe. Il lhe tube is smoky,
check fo r
a
se ized p iston ring .
Cvlinder compre-ssion is too low, ()r eng ine i$ hard to start
Blown cyl inder head gasket
Worn , stuck Or b roken p iston ring
Worn or damage d cy linder or piston
Cylinder com pressi on is t oo high, or eng ine overhEl1lI $ or
kn()(;ks
Carbon depo$il $ on the cylinder head andlo r p iston
crow n
8-2
Piston sounds
Worn cyli nder, pislon andlor piSTon ri ng
Wo rn pisto n pin hole and piston pin
Worn connecting rod small end
Excessive smoke
- Worn, stuck or brOken piston ring