Honda XR80R Service Manual page 100

CYLINDER HEAD/VALVES
TORQUE VALUES
Cylinder head cover bolt
Ciilmsha!t holder nut
Ca m sproc ket bolt
Spark pl ug
Valve ii1dlU$ling b olt l oc~
1'1\1\
12 N ' m
(1.2
kg /·m. 9 IbHI)
20 N ' m (2.0 kgf·m .
14
Ib!,ft)
12 N' m
0 .2
kg!·m. 9 lbHt )
14 N ' m ( 1.4 kg f' m. 10 Ibf.fl)
10 N'm (1 .0 ~gf·m. 1 Ibl-f\)
TOO L
Valve ii1djusting wre nch. 8 X 9 mm
Valve ii1djus!er B
Valve spring compressor
Valve guide driver, 5.5 m m
Valvo g u ide rcamer. 5.5 mm
Viillve seat cutters
Seiilt CU ller, 27.5 mm (45' IN )
Seat cu tt er. 24.5 mm (45' EX )
Fl al CU ller, 25 mm (l 2'IN )
FI ... t cutter. 22 mm (3 2' EX)
Interior cutter. 22 mm (60'I N/EX)
Cutter holder. 5.5 m m
TROUBLESHOOTING
07708·0030 100
07908·KE90000
07757,00 10000
077 42·00 10 100
07 984-0980001
077 80-00 10200
07780-0010100
07780-00 12000
077 80·00 12601
07780·00 14000
07781 ·0010101
Equivalen t commerci aly ... va i lab le in U.S. A .
or 0790B·KE90200 (U, S.A. onl y)
Or 079 42·3290100 (U.S.A . onl y )
Or 07984.0980000
- These Ite com mclcillily a"ail ... ble in U.S.A.
Engine top·end prob lems usually affect angine perfo rm ance. These problem c ... n be diagoosed by a comprenion le sl or
by Iracing engine noises 10 Ihe lop·end w 'th a $Oun ding rod stethosco pe.
II the performance;s pOo . ... t low speeds, check 10 ' w h,le smo ke i n Ihe criilnkcase breather tube. I! Ihe IUbe;S smoky
check for a seiled piston ring (Secl ion 8).
Com prHsion 100 low. hlrd surting o. poor perlormance
It
low speed
Valves :
- Incorrect vlliv e adjustment
- Burnod or bent va lve
- Incorrect valve T imi ng
- BrOker! valvo spring
- Une"en "al"e SCiillin g
Cylinder head
- Leaking o r damiilged hud gasket
- Warped or cracked cylindef head
Worn cy linder. poston or piSTon rongs (section 8)
Comp. ession 100 high, over heating or knockIng
EKcess",e Ciilr bon bu i ld 'u p o n p i STo n Cf own or on
combust ion Chamber
Excessiv e smoke
Cyhnd er head:
- Worn valve stem or "al"e guide
- Damaged STem sea l
W orn cylin der. piston or piston rings rsoct ion 8)
7-2
Excessive noise
Cylinder head:
- lncorreCI "al"e adjustmenT
- STicking va lve o r broken v " l"c spring
- Damiilged o r w o rn camshaft
- Loose or w Orn ca m chain
- W orn or damaged cam ch ain
-
Worn or damage d c am ch ain lensiooer
- W orn cam
sproc~et
teet h
- Worn rocke. arm an d/or sha ft
Wo rn cyl inder, piston or piston ri ngs (section 8 1
Rough idle
• Low tyliode' co m pression