Yanmar 128620-42130 Cover O-Ring for 6CX
The Yanmar 128620-42130 is the genuine replacement cover o-ring for 6CX Series engines. It is one of the cheapest parts in the pump and one of the few that can stop it working altogether.
Fitting is where most of them are lost. Clean the groove so nothing is trapped underneath, lift the old ring out with a plastic or brass pick rather than a screwdriver, and lubricate the new one lightly before the joint is closed. A ring nicked on a sharp edge during assembly seals well until the engine is running and then weeps, which sends people looking for a fault that is not there. Check the groove and the mating face for corrosion at the same time, because a pitted groove will not hold a new ring any better than it held the old one.
Key Features
- Genuine Yanmar replacement cover o-ring
- Fits 6CX Series engines
- One per pump
- Restores a positive seal at the joint
- Prevents both leaks and air being drawn in on the suction side
- Inexpensive part worth renewing whenever the joint is opened
Applications
- 6CX Series engines
- Raw water pump rebuilds and impeller changes
- Curing a leak or a weep at a pump joint
- Tracing air drawn into the suction side
- Reassembly after any joint in the pump is opened
- Spring commissioning and layup service
Specifications
- Brand: Yanmar
- Manufacturer: Yanmar Marine
- Manufacturer Part Number: 128620-42130
- Part Type: Cover O-Ring
- Fits: 6CX Series engines
- Quantity Used: One per pump
- Condition: New
Frequently Asked Questions
Q: How do I avoid damaging the new ring?
Use a plastic or brass pick on the old one, clean the groove so nothing is trapped underneath, and lubricate the new ring lightly before closing the joint.
Q: Should I replace all the pump seals at once?
If the pump is open, yes. They have all seen the same hours and the same water, and reaching them is most of the work.
Q: What makes an O-ring swell?
Absorption of whatever it is sealing, or contact with a fluid the material was not chosen for. A ring noticeably larger than the new one is telling you something is wrong.
Q: Does a cover O-ring differ from a port O-ring?
They seal different joints and are not interchangeable. Both are static seals, but each is sized for its own groove.
Not sure this is the right part? Send us a Picture of the Pump Plate on your pump and the CLR Marine team will confirm the correct cover o-ring.
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