Honda CB900F Service Manual page 196

CYLINDER HEAD/VALVES
TOOLS
Compression gau ge atta chment
Va lve spring compres sor
Valve spring compressor atta chm ent
Tappet hole protector
Valve guide dr iver
Valve gu ide ream er, 4.508 mm
Valve seat cu tte rs
Seat cutte r, 27.5 mm 145' IN/EX)
Flat cutte r, 27 mm 1 32' EX )
Flat cutter, 30 m m 1 32 ' IN )
Int erior c utte r, 24 mm 1 60' IN/EX)
Cutte r hold er, 4.5 mm
TROUBLESHOOTING
07RMJ-M Y50100
07757 -0010000
07959-KM30101
07 HMG-MR70002
077 43--0020000
07HMH-ML00101
0778 0--0010200
077 80--0013300
0778 0--0012200
07780--0010600
07781--0010600
Equivalent comm erciall y avai lable
- t hese are co m merci ally avai labl e
Ro ugh idle
• Low cy li n de r co m press io n
- Sti cking va lve or brok en valv e sp ring
- Damaged or worn camshaft
- Loose or wo rn cam chai n
- Worn or damaged cam chain
- Worn o r damaged cam cha in te nsion er
- Worn cam sproc ket t eeth
Wo rn cy li nder, pi ston or pisto n ring s (sec tio n 12)
Engine top-end prob lem s usu all y affec t en gine performan ce. These probl em s can be diagnosed by a compress ion t est o r
by trac ing engine no ises t o th e top-e nd w it h a so und ing rod ste t hosco pe.
If the perfo rm ance is poor at low speeds. check fo r w hite smoke in the cra nkcase breath er t ube. If th e tube is smoky, check
for a seized piston ri ng (Section 12).
Compression too low, hard starting or poor performance at low speed
Valves:
- Incorrect valve adj ust m ent
- Burn ed o r ben t va lve
- Incorrect va lve timing
- Broken valve spr in g
- Un even v alve seat ing
Cyli nde r he ad:
- Leaking o r damaged head gasket
- Warped o r cracked cy li n de r hea d
Worn cylinder, piston o r pi st on rings (sect io n 12)
Compression too high, overheating or knocking
Excessive ca rbo n build- up o n piston crown o r o n co m bus -
ti on cha m be r
Excessive smoke
Cyli nder head:
- Wo rn v alve ste m o r v alve guide
- Dam ag ed stem sea l
Wo rn cy lin de r, piston o r pi ston rin gs (sect io n 12)
Excessive noise
Cylinder head:
- Inco rrect va lve adju st ment
8-3