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-   -   Belt driven raw water fuel pump assembly (https://www.offshoreonly.com/forums/general-q/387363-belt-driven-raw-water-fuel-pump-assembly.html)

Helmwurst 02-05-2026 07:00 PM

I already rebuilt my sea pumps and pre-lubed the bearings with this stuff that oil will never penetrate. This stuff is used on Dyno bearings. My pumps are also drilled and tapped for the relief tubes. My main issue is to find a fuel pump that will work w/o leaking into the oil reservoir. The lube is for the fuel pump arm bushing.

Rookie 02-05-2026 07:04 PM


Originally Posted by Eddienel (Post 4942422)
I know a guy that’s running the Amazon ones and not having any issues at all. I’m sure others will chime in.

https://a.co/d/09MU3B4K


I know someone that has been running 2-$150 ebay pumps with no issues. I keep a spare eBay pump on my shelf for just incase.

Eddienel 02-06-2026 06:42 AM


Originally Posted by Rookie (Post 4942524)
I know someone that has been running 2-$150 ebay pumps with no issues. I keep a spare eBay pump on my shelf for just incase.

Im fixing to buy a spare and keep it in the boat.

Dish8999 02-06-2026 09:16 AM

Thank you all for the knowledge and input especially the detailed break down with pictures, learning is occurring!!!!!

Helmwurst 02-07-2026 08:59 AM

I honestly don't remember what fuel pump i used https://www.offshoreonly.com/forums/...lies/frown.gif ...that was like 25yrs ago now....i want to say it was an Edelbrock pump i used but it may have been a holley just the same...sorry

Walley, thanks for that. If i could find an automotive pump with the right arm to mount on the sea pumps, I would do it and modify it to vent to the flame arrestor. In addition to all of that, the Holley's have a larger in/out port which I would also like to have.

Dish8999 02-10-2026 01:23 AM


Originally Posted by Griff (Post 4942517)
Have you ever changed the gear lube?? It gets fuel diluted and over pressurizes.
The sea pump rebuild kits are on ebay, but you need a hydrailic press do it.

This is a new to me boat. I have not changed the lube, I just noticed after my last outing that lube had to be coming from that location. The over pressure would make sense. So if the pump isn’t squeaking it may not need a rebuild just a reseal and fresh lube?

Wally 02-10-2026 07:37 AM


Originally Posted by Dish8999 (Post 4942723)
This is a new to me boat. I have not changed the lube, I just noticed after my last outing that lube had to be coming from that location. The over pressure would make sense. So if the pump isn’t squeaking it may not need a rebuild just a reseal and fresh lube?

If fuel is leaking into the oil chamber then its only a matter of time before it all goes south when there's no more oil in there to act as a lubricant. You may have gotten lucky and caught it early...so it may be just a quick re-seal and a new fuel pump and back in business...or you may get extra lucky and its actually just a bad seal so you can do seals and oil change and back on the water...just depends on whats going on.

Dish8999 02-11-2026 03:27 PM


Originally Posted by Wally (Post 4942729)
If fuel is leaking into the oil chamber then its only a matter of time before it all goes south when there's no more oil in there to act as a lubricant. You may have gotten lucky and caught it early...so it may be just a quick re-seal and a new fuel pump and back in business...or you may get extra lucky and its actually just a bad seal so you can do seals and oil change and back on the water...just depends on whats going on.


Ok so it needs taken apart and replace all the seals at a minimum if it doesnt need new bearings and a new shaft. I think I’m understanding that part. Why would the fuel pump need to be replaced? Is that the seal thats failing and leaking into the oil chamber?

Helmwurst 02-12-2026 08:18 AM


Originally Posted by Dish8999 (Post 4942818)
Ok so it needs taken apart and replace all the seals at a minimum if it doesnt need new bearings and a new shaft. I think I’m understanding that part. Why would the fuel pump need to be replaced? Is that the seal thats failing and leaking into the oil chamber?

The fuel pump is causing the issue. It is leaking fuel into the oil chamber and causing the sea pump seals to fail.

Wally 02-12-2026 09:15 AM

Yes if you have the style of fuel pump that can be taken apart, you will see once its open that the arm of the fuel pump that rides on the cam in the seawater pump is connected to the diaphragm that pumps the fuel to the engine. Once that diaphragm ruptures it starts leaking....only problem is the orientation of the fuel pump on top of the sea water pump makes it leak into the chamber where the oil is for lubrication. So the entire oil chamber has to fill up with fuel before it will start to travel up that "overflow" tube up to the intake/air filter. Thats assuming all the seals hold up and don't leak before it gets up the the top.
I'd say probably 80% of the time the sea water pumps are shot cause the owners didn't know it was happening until its seizing the bearings from lack of lubrication :(
Others get lucky and catch it before any damage happens and are able to rebuild them for cheap :)


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