I cant fill the fuel/water filter separator with the primer bulb

[JEFR1957]

Hi, need help with this problem. This a 48 HP Yamaha with 10 microm filter separator instaled in between the primer bulb and the portable tank. I cant fill the filter with the primer bulb, unless the engine is running.

[rodbolt17]

its kinda simple if you actually think about it.
what is the primer bulbs sole function in life?

how much fuel is still in the lines and fuel bowls when you try to refill the water separator.

face palm about now.

[joe009]

what i do is to fill the fuel/water filter with gas before you screw it back in

[JEFR1957]

HI, I try it in two different situations. Removing the water from the filter, leaving the clear bowl empty. And replacing the filter totally empty, with no gas in it. I did it on porpose just to see if it can be filled with the primer bulb.
The line from tank to filter have some fuel and the tank is complety full.

[JEFR1957]

Hi JOE009, it works that way. What worry to me is running out of gas out there and have to remove filter to fill with gas just to prime the system. Before I have the primer bulb in between the tank and the filter, and can fill the filter and the line up to the motor with no problem at all.

[boscoe99]

A primer ball pumps fuel much better than it sucks fuel. Particularly so when there is no air within the primer ball as there may be if the ball is placed after the filter.

If the primer ball is between the tank and the filter it will (should anyway) remain full of fuel (and only fuel) when the filter is changed. I presume the ball is below the level of the filter.

Also, hold the ball vertically with the outlet on top. Gravity will then assist the check valves in doing their job.

[JEFR1957]

Hi boscoe99, thanks for your comments. That’s exactly what’s happens, even though I hold the pump looking to the sky, it just sucks the gas in the line after the filter, but has not enough power to sucks from the tank.
RACOR recommend not to install the ball before the filter because the pumping acting emulsifies the water and reduce the efficiency of the separator. That’s the reason I prefer to maintain the bulb after the filter.

[nuthouseinva]

My primer bulb is after the filter close the motor. After I changed my filter, I couldn't get the bulb to pull fuel through the lines to fill the filter and get solid prime on the lines. A quick turn of the key put enough suction on the line to get the pressure I needed to get the system primed again. No problems after that.

[JEFR1957]

Interesting, let me try it. I did it before with gas in the engine and as soon as the engine starts the filter start filling. But like you said, probably with just a couple of cranks, it put enough pressure in the line to sucks from the tank. Thanks…

[99yam40]

if the carbs, lines, and pump on motor are full of fuel then there is no place for the air in filter to go.
You cannot fill the filter up if you cannot push the air out that is in it.
Once you crank up motor it will suck the air out eventually as the fuel is used up the floats drop opening the needle valves allowing fuel and air into the bowls and discharge the air out the vents in the carbs
Rod tried to tell you this a few posts back

[JEFR1957]

Thanks 99yam40, totally right. I didn't think enough to understand how the system works. Make me feel ??? . I did’t realize what robbolt17 try to said.
Thanks to all of you...

[rodbolt17]

1 2 3 face palm

its fairly simple.
if NOTHING can move cause the needles are closed then simply nothing moves.

all that primer bulb does is PRIME the system.
if you stood your car on end every night a car would have a fuel primer system.

[99yam40]

if you stood your car on end every night a car would have a fuel primer system.

They (EFI) kind of do now a days with the pump in the tank, comes on at key on and pressures up the system with liquid fuel

[boscoe99]

They (EFI) kind of do now a days with the pump in the tank, comes on at key on and pressures up the system with liquid fuel

Wouldn't that be nice to have on an outboard?

Cool continuously filtered fuel as the excess gets recirculated from the motor back to the tank in the boat and goes through the tank filter and one motor filter, over and over.

No fuel coolers on the motor.

No VST and related crap to deal with.

No lift pump required.

Maybe with the sealed tanks that have been mandated by the EPA we will see this sooner than later. Only many, many years late.