Yanmar 104211-42050 Cam for 2GM and 3GM
The Yanmar 104211-42050 is the factory cam used in the sea water pump fitted to 2GM and 3GM Series engines. It is a fixed part that does its work by being in the way: every vane on every revolution is deflected by it, and the seal between vane tip and cam face is where pumping actually happens.
Cams wear where the vanes bear on them, and in salt water they corrode as well. A cam with a groove, a step or a corroded face no longer gives the vanes a continuous surface to seal against, so water slips back past the impeller and the flow falls away. It is easy to miss because the impeller looks fine - the new one simply does not restore the flow the engine had when it was new.
Key Features
- Genuine Yanmar replacement cam
- Fits the sea water pump fitted to 2GM and 3GM Series engines
- One per pump
- Restores the sealing face the impeller vanes bear on
- Recovers flow lost to a grooved or corroded cam
- Direct replacement, no modification required
Applications
- the sea water pump fitted to 2GM and 3GM Series engines
- Raw water pump rebuilds
- Restoring flow that a new impeller alone did not recover
- Repairing a pump after the cam screw worked loose
- Service on a pump that has run in salt water for years
- Spring commissioning and layup service
Specifications
- Brand: Yanmar
- Manufacturer: Yanmar Marine
- Manufacturer Part Number: 104211-42050
- Part Type: Cam
- Fits: The sea water pump fitted to 2GM and 3GM Series engines
- Quantity Used: One per pump
- Condition: New
Frequently Asked Questions
Q: A new impeller did not restore my flow. Why?
The cam and the wear plate are the usual answers. Both form sealing surfaces for the impeller, and a worn one lets water slip back instead of being carried to the outlet.
Q: What happens if the cam screw comes loose?
The cam shifts in the body and the impeller runs into it, which usually destroys the impeller and can damage the body. Check the screw is tight whenever the cover is off.
Q: Is the cam handed?
Yes, it has one correct position and orientation in the body. Note how the old one sits before removing it, because a cam fitted the wrong way round stops the pump working entirely.
Q: Can a worn cam be dressed rather than replaced?
Removing material changes how far the vanes are deflected, which changes the pump output. On a part this small it is not worth the compromise.
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 cam.
CLRMarine
