What am I looking at? Gulfstream 232

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jmenende

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Howdy folks. Just upgraded to a 1999 gulsftream 232 with dual ox66 150hp. I think these are fuel pumps but im not sure. The lines come from the valves, through them and out to the engine.

Also, I have included another foto of a valve that connects to the toilet outlet. What does it do?

Thanks in advance.
 

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I think those are lift pumps but I am not sure why you would have them with OX66 motors that have their own low pressure pumps.

The second pic is the overboard discharge/pump out selector valve. Normally it should be in the pump out position and either disabled with a lock, a tie wrap, or by removing the handle. It would only be unlocked when discharging waster tank contents in legal water areas.

Technically even if the selector is in the dockside discharge position but not locked/secured, you can be fined.
 
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The OX's lift pumps have a finite lifespan because of being made out of a thin rubber diagphram. Generally, an electric lift pump is more reliable.

That said, I've neve personally seen an electric fuel pump that looks like that - not to say that I've seen everything, though. But I'm curious aobu the "T" being used.
 
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The valve controls waste outlet. Center hose is the pickup from the shi_tank. one hose goes to a deck fitting for dockside pumpout. the other goes to a macerator pump. from there it uses a smaller hose to an underwater thruhull that also has a valve. You also have another valve for water inlet to the head (toilet).

The other things are definitely fuel pumps but I've never seen them before. I had OX66s. Did not have those. They are unusual. Maybe they recirculate?
Interesting. Can you see a name or part#?
 
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SkunkBoat said:
The valve controls waste outlet. Center hose is the pickup from the shi_tank. one hose goes to a deck fitting for dockside pumpout. the other goes to a macerator pump. from there it uses a smaller hose to an underwater thruhull that also has a valve. You also have another valve for water inlet to the head (toilet).

The other things are definitely fuel pumps but I've never seen them before. I had OX66s. Did not have those. They are unusual. Maybe they recirculate?
Interesting. Can you see a name or part#?
Click to expand...
Will take a closer look and report back.
 
DennisG01 said:
The OX's lift pumps have a finite lifespan because of being made out of a thin rubber diagphram. Generally, an electric lift pump is more reliable.

That said, I've neve personally seen an electric fuel pump that looks like that - not to say that I've seen everything, though. But I'm curious aobu the "T" being used.
Click to expand...
That loop between the inlet and outlet is strange. My guess is that the fittings are check valves and the loop passes gasoline when the primer bulb or motor fuel pumps 'suck' gas.
I also thought that the devices were related to some sort of fuel flow monitoring sensor but that seemed less likely. That said, if you follow the fuel lines you can see in the upper right area some sort of device with a wire going into it that the fule line connects to. That may be a fuel floe sensor.
 
seasick said:
That loop between the inlet and outlet is strange. My guess is that the fittings are check valves and the loop passes gasoline when the primer bulb or motor fuel pumps 'suck' gas.
I also thought that the devices were related to some sort of fuel flow monitoring sensor but that seemed less likely. That said, if you follow the fuel lines you can see in the upper right area some sort of device with a wire going into it that the fule line connects to. That may be a fuel floe sensor.
Click to expand...
I figured its some valve actuated by the key switch. There is one on each side after those "fuel pumps" that never vibrate. Im getting ready to install a 12v modern pump after the filter and bypass all that. If it works then i will proceed to eliminate the internal lift pumps on the engine. The simpler, the better. Thats the plan.
 

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jmenende said:
I figured its some valve actuated by the key switch. There is one on each side after those "fuel pumps" that never vibrate. Im getting ready to install a 12v modern pump after the filter and bypass all that. If it works then i will proceed to eliminate the internal lift pumps on the engine. The simpler, the better. Thats the plan.
Click to expand...
Those are fuel burn sending units. Don't get rid of those! The readout is on your yamaha gauges
 
I am not sure if bypassing/removing the low pressure fuel pumps is a good idea. As long as they are in good shape, they aren't a big deal. They do need to be replaced but usually last many years. The original pumps had weaker diaphragms than newer replacements.
My concern is too much pressure stressing the LP pumps or VST since there will not be a control signal to tell the external pumps to turn off. Historically the fuel system of the OX66 has been very reliable.
 
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