Yanmar — Compression pressure measurement
Testing & diagnosis · Engine cylinder
From a Yanmar service manual covering: 2TNV70, 3TNV70, 3TNV76. Check it applies to your exact model before use.
Applies to: Yanmar 2TNV70, Yanmar 2TNV70 engine, Yanmar 3TNV76 engine
Procedure
- Warm engine, then remove fuel injection pipe and valves from cylinder.
- Crank engine with stop handle at stop position before installing adapter.
- Install compression gage adapter and gage with gasket.
- Crank with starter until gage reading stabilizes.
- Compare with standard: 2/3TNV70 3.24±0.1 MPa; 3TNV76 3.43±0.1 MPa.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 2/3TNV70 eBay $51.99 FridayParts $9.99 SinoCMP $79.00 standard 3.24±0.1 MPa (33±1 kgf/cm2)
- 3TNV76 eBay $12.99 FridayParts $9.80 SinoCMP $58.00 standard 3.43±0.1 MPa (35±1 kgf/cm2)
Full service-parts list: Yanmar 2TNV70 →, Yanmar 3TNV76 engine →
Source: Yanmar 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.