- Marine Engines:
- 3406E (S/N: 9WR1-UP)
- C18 (S/N: CKH1-UP; CYN1-UP; C1J1-UP)
- C15 (S/N: RLA1-UP)
Description of Change: The engines that are listed above contain inlet valve seats that have been changed. These changes to the inlet valve seats were made in order to limit corrosion.
Adaptable To: Check the part numbers 175-3617 Valve Seat Insert and 108-5912 Valve Seat Insert for corrosion. If necessary, replace the corroded part with 108-5912 Valve Seat Insert. The new 108-5912 Valve Seat Insert is made from a material that is corrosion resistant. Machining is required to seat the valves properly. Refer to Engine Specifications, "Cylinder Head Valves" for the proper valve seat dimensions.
Check the part numbers 226-9199 Seat Insert and 224-3983 Seat Insert for corrosion. If necessary, replace the corroded part with 224-3983 Seat Insert. The new 224-3983 Seat Insert is made from a material that is corrosion resistant. No machining is allowed on 224-3983 Seat Insert.
| Old Valve Seats | Replace with New Valve Seats |
| 108-5912 Valve Seat Insert (finish in-place seats) | 108-5912 Valve Seat Insert (requires machining after assembly) |
| 175-3617 Valve Seat Insert (finish in-place seats) | 108-5912 Valve Seat Insert (requires machining after assembly) |
| 226-9199 Seat Insert (precision seats) (no machining allowed) | 224-3983 Seat Insert (no machining allowed) |
| 224-3983 Seat Insert (precision seats) (no machining allowed) | 224-3983 Seat Insert (no machining allowed) |