LP pump on Yanmar 2GM20F

Jul 7, 2004
8,451
Hunter 30T Cheney, KS
Disconnect and remove. Basic and easy. There is a screen inside the pump that can get clogged. Make sure it’s clean and working and reinstall. My last boat the pump was leaking so I just bought a new one and replaced.

good luck.
Is this a common problem? I doubt mine has ever been checked. Wondering if I need to add it to my regular maintenance plan.
 
Jan 4, 2006
6,984
Hunter 310 West Vancouver, B.C.
This way, in the case of a main pump failure, I can manually start the emerg pump.
I may be missing something here, but as previously mentioned, a failure of your lift pump to operate MUST NOT cause a loss of fuel flow to the HP pump. This is shown here:

Positive Shut Off Valve - No.JPG


On an H-310, the fuel tank is pretty much above the level of the HP pump exept when near empty. You will not notice any change in running WOT if you shut off the electric lift pump. Not unless you are near empty and then all bets are off. Do you really need a spare for your set up ?

The primary filter bleed valve
What is this ?
 
Jul 2, 2019
102
Hunter 310 Pine Beach, NJ
I may be missing something here, but as previously mentioned, a failure of your lift pump to operate MUST NOT cause a loss of fuel flow to the HP pump...

On an H-310, the fuel tank is pretty much above the level of the HP pump exept when near empty. You will not notice any change in running WOT if you shut off the electric lift pump. Not unless you are near empty and then all bets are off. Do you really need a spare for your set up ?

Primary bleed valve
What is this ?
Apparently I don't need a second pump if the system can operate with no lift pump (as long as it is primed). I do understand that the pump must have an internal forward bypass to allow fuel flow while pump is stopped or DOA.

What I am calling primary bleed valve is the valve shown in my diagram. It is used for priming (bleeding) the primary filter / separator by bypassing back to the tank via the injector return line.
 
Jan 4, 2006
6,984
Hunter 310 West Vancouver, B.C.
It is used for priming (bleeding) the primary filter / separator by bypassing back to the tank via the injector return line.
Doesn't your primary filter body have a vent screw at its highest point ? Even my cheapo Racor 110 has a vent screw.

If you just look at passing fuel only through > > > > > the filter, I think you may still have some air in the upper filter body which will ONLY come loose and stall your engine when you need it most, such as coming into the dock a little too fast when the smartass nextdoor with the obnoxious powerboat is watching you :facepalm:.
 
Jul 2, 2019
102
Hunter 310 Pine Beach, NJ
Doesn't your primary filter body have a vent screw at its highest point ? Even my cheapo Racor 110 has a vent screw.

If you just look at passing fuel only through > > > > > the filter, I think you may still have some air in the upper filter body which will ONLY come loose and stall your engine when you need it most, such as coming into the dock a little too fast when the smartass nextdoor with the obnoxious powerboat is watching you :facepalm:.
Hmmm. Very good point. I was merely taking the idea from Alan Gomes who posted on this thread that he plumbed it that way. Looks like the most sensible approach is to mount the filter so its easily removed from the bracket at cleaning time. That would allow tilting and turning to hopefully coax any air bubble to the bleed screw.
 
Nov 21, 2012
683
Yamaha 33 Port Ludlow, WA
Also consider replacing the bolts on the pump with studs if your access is poor.. It can be really, really difficult to thread the bolts and align the gasket.