Suzuki DF 25 Service Manual page 135

7-18 POWER UNIT
2. Position cylinder head on cylinder.
3. Apply engine oil to cylinder head bolts and tighten them gradu-
ally as follows.
(a) Tighten all bolts to 50 percent (%) of specified torque
according to numerical order in figure.
Cylinder head bolt :
1 st step 10 mm 30 N . m (3.0 kg-m, 21.5 lb.-ft.)
8 mm 12 N . m (1.2 kg-m, 8.5 lb.-ft.)
(b) Loosen all bolts to 0 N . m ( 0 kg-m , 0 lb.-ft. ) according
to reverse order in figure.
(c) Again tighten all bolts to 50 percent (%) of specified torque
according to numerical order in figure.
Cylinder head bolt :
3 st step 10 mm 30 N . m (3.0 kg-m, 21.5 lb.-ft.)
8 mm 12 N . m (1.2 kg-m, 8.5 lb.-ft.)
(d) Finally tighten all bolts to specified torque according to
numerical order in figure.
Cylinder head bolt :
10 mm 62 N . m (6.2 kg-m, 45.0 lb.-ft.)
Final step
8 mm 25 N . m (2.5 kg-m, 18.0 lb.-ft.)
4. Install timing chain. (see page 7-14)
5. Adjust valve clearance. (see page 2-9)