89 TransAlp Manual Cylinder Head Valve 9 1

9. CYLINDER HEAD/VALVE

SERVICE INFORMATION	9-1	CYLINDER HEAD ASSEMBLY	9-14
TROUBLESHOOTING	9-2	CYLINDER HEAD INSTALLATION	9-15
CYLINDER HEAD COVER REMOVAL	9-3	CAMSHAFT INSTALLATION	9-16
CAMSHAFT REMOVAL	9-4	CYLINDER HEAD COVER
CYLINDER HEAD REMOVAL	9-8	INSTALLATION	9-19
VALVE GUIDE REPLACEMENT	9-10
VALVE SEAT INSPECTION/
REFACING	9-11

SERVICE INFORMATION

GENERAL

•    To service the cylinder head, the engine must be removed from the frame; you can service the cylinder head cover, rocker arm, camshaft, cam chain and cam chain tensioner without removing the engine.

•    Camshaft lubricating oil is fed through an oil pass pipę. Be surę the holes in the oil pass pipę bolts are not clogged.

•    During assembly apply M0S2 pastę grease (page 2-10) to the camshaft holders, camshaft journals of the cylinder head, rocker arm shafts, rocker arm slipper faces and valve stems to provide initial lubrication.

SPECIFICATIONS

Unit: mm (in)

ITEM				STANDARD	SERVICE LIMIT
Compression pressure				1177 ± 98 kPa (12.0 ± 1.0 kg/cm^J, 171 ± 14 psi)	—
Camshaft	Cam lobe height	IN		38.189 (1.5035)	38.17 (1.503)
		EX		38.213 (1.5044)	38.19 (1.504)
	Journal O.D.			21.959-21.980 (0.8645-0.8654)	21.95 (0.864)
	Runout			0.030 (0.0012)	0.05 (0.002)
	Oil clearance			0.050-0.111 (0.0020-0.0044)	0.13 (0.005)
Rocker arm	Rocker arm I.D.	IN/EX		12.000-12.018(0.4724 0.4731)	12.03 (0.474)
	Rocker arm shaft O.D.	IN/EX		11.966-11.984 (0.4711-0.4718)	11.96 (0.471)
Valves and valve guides	Valve stem O.D.	IN		5.475-5.490 (0.2156-0.2161)	5.45 (0.215)
		EX		6.555-6.570 (0.2580-0.2587)	6.55 (0.258)
	Valve guide I.D. --»— ----- - - - -	IN		5.500-5.520 (0.2165-0.2173)	5.56 (0.219)
		EX		6.600-6.620 (0.2598-0.2606)	6.65 (0.262)
	Stem-to-guide clearance	IN		0.010-0.045 (0.0004-0.0018)	0.10 (0.004)
		EX		0.035-0.050 (0.0014-0.0020)	0.11 (0.004)
	Valve seat width			0.9-1.1 (0.035-0.043)	1.5 (0.06)
Valve springs	Free length	OUTER	IN	42.14 (1.659)	40.44 (1.592)
			EX	42.83 (1.686)	41.13 (1.619)
		INNER	IN	38.11 (1.500)	36.41 (1.433)
			EX	38.81 (1.528)	37.11 (1.461)
Cylinder head warpage				—	0.10 (0.004)