Kubota WG972-GL-E3F — Compression Pressure
Testing & diagnosis · Cylinder compression
For the Kubota WG972-GL-E3F, from the Kubota service manual.
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Before you start
- Always use a fully charged battery for performing this test.
- Replace the muffler/converter gasket with a new one.
Procedure
- Operate the engine until it is warmed up.
- Stop the engine.
- Remove the air cleaner, the muffler/converter and all spark plugs.
- Set a compression tester with the adaptor to the spark plug hole.
- Operate the engine with the starter for 5 to 10 seconds keeping throttle valve fully open and read the maximum compression pressure.
- Repeat for each cylinder.
- If below the allowable limit, apply a small amount of oil to the cylinder wall and measure again.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Compression pressure factory specification: 1.27 MPa (13.0 kgf/cm2, 185 psi)
- Allowable limit: 0.88 MPa (9.0 kgf/cm2, 130 psi)
- Variances in cylinder compression values should be under 10 %
Source: Kubota service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.