Perkins — To fit the cylinder head assembly (engine types AJ to AQ and YG to YK)
Repair & overhaul
From a Perkins service manual — check it applies to your exact model before use.
Browse Perkins generators & specs →
Before you start
- Do not use a lever to separate the cylinder head from the cylinder block
Procedure
- Clean bottom face of cylinder head and top face of cylinder block; ensure no debris in bores
- Put cylinder head joint in position stamped FRONT TOP
- Fit two 1/2 UNF guide studs in positions 16 and 21 or 25 and 30; put cylinder head in position, engage location pins
- Lubricate setscrew threads and thrust faces; engage setscrews and remove guide studs
- Tighten setscrews to 110 Nm in sequence; repeat
- Tighten setscrews a further part-turn by length (S 150°, M 180°, L 210°)
- Fit push rods, rocker assembly, set valve tip clearances, fit atomisers and high-pressure pipes
Tools required
- Angle gauge 21825607 Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 110 Nm (80 lbf ft) 11,1 kgf m
- High-pressure pipe nuts 22 Nm (16 lbf ft) 2,2 kgf m
Source: Perkins 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.