Ford LSG 875 — Compression Test (Compression Gauge Check)
Testing & diagnosis · Engine cylinders
For the Ford LSG 875, from the Ford service manual.
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Procedure
- Be sure crankcase oil is correct viscosity and battery is charged.
- Operate engine minimum 30 minutes at 1200 rpm until normal operating temperature; remove all spark plugs.
- Set carburetor throttle plates in wide open position.
- Install compression gauge in No. 1 cylinder.
- Crank engine at least five compression strokes, record highest reading.
- Repeat test on each cylinder.
- Lowest reading cylinder must be within 75% of the highest reading.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Lowest reading cylinder within 75% of highest
Source: Ford 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.