Checking, Disassembling And Servicing; Checking And Adjusting; Engine Body - Kubota WG972-E2 Workshop Manual

WG972-E2, DF972-E2, WSM

4. CHECKING, DISASSEMBLING AND SERVICING

[1] CHECKING AND ADJUSTING

(1) Engine Body

Compression Pressure
1. Run the engine until it is warmed up.
2. Stop the engine.
3. Remove the air cleaner, the muffler and all spark plugs.
4. Set a compression tester with the adaptor to the spark plug hole.
5. Run the engine with the starter for 5 to 10 seconds keeping
throttle valve fully open and read the maximum compression
pressure.
6. Repeat steps 4 and 5 for each cylinder.
7. If the measurement is below the allowable limit, apply a small
amount of oil to the cylinder wall through the spark plug hole and
measure the compression pressure again.
8. If the compression pressure is still less than the allowable limit,
check the top clearance, valve clearance and cylinder head.
9. If the compression pressure increases after applying oil, check
the cylinder wall and piston rings.
■
NOTE
• Check the compression pressure with the specified valve
clearance.
• Always use a fully charged battery for performing this test.
• Variances in cylinder compression values should be under
10 %.
Factory spec.
Compression pressure
Allowable limit
S-14
GASOLINE / LPG ENGINE
1.27 MPa
2
13.0kgf/cm
185 psi
0.88 MPa
2
9.0kgf/cm
128 psi
W1048776
KiSC issued 01, 2006 A