Engine Body; Checking And Adjustment - Kubota Z400-B Handbuch

ENGINE BODY
CHECKING AND ADJUSTMENT
Compression Pressure
1. Run the engine until it is warmed up.
2. Stop the engine and remove the air cleaner, the muffler
and all nozzle holders.
3. Set a compression tester (Code No.: 07909-30200) with
the adaptor to the nozzle holder hole.
4. Run the engine with the starter at 200 to 300 rpm for 5
to 10 seconds and read the maximum compression
pressure.
5. Measure the compression pressure several times.
6. If the measurement does not reach the allowable limit,
apply a small amount of oil to the cylinder wall through
the nozzle holder hole and measure the compression
pressure again.
7. If the pressure is still less than the allowable limit, check
the top clearance, valve and cylinder head.
8. If the pressure increases after applying oil, check the
cylinder wall and piston rings .
• NOTE:
• Check the compression pressure with the specified valve
clearance (See page S-63) .
• Variances in cylinder compression values should be under
10%.
3.09 MPa
I
Factory specification
31.5 kgf/cm'
I
448 psi
Compression pressure
2.32 MPa
!
Allowable limit 23,7 kgf/cm'
337 psi
Top Clearance
_M. """.._ .....__
1. Remove the nozzle holder and lower the piston in the
cylinder.
2. Insert a high-quality fuse from the nozzle holder hole on
the piston [except where it faces the valve or the combus ­
tion chamber insert.]
3. Rotate the flywheel until the piston is raised and lowered
again.
4. Take out the flattened fuse carefully and measure its
thickness with vernier calipers.
5. If the measurement is not within the specified values,
check the oil clearances of the crankpin journal and the
piston pin.
0.60 to 0,80mm
Top clearance Factory specification
0,0236 to 0,0315 in,
S-61