water separator

[slate1234]

Hi all I'm running a 1985 8hp evinrude on a 2.7m sib, could I fit a water separator to the transom of the sib and if so which side of the primer bulb is best
Thanks

 

[Grub54891]

Re: water separator

After the primer bulb,easier to fill the filter that way.
Grub

 

[dingbat]

Re: water separator

After the primer bulb,easier to fill the filter that way.
Grub

.....and you don't have to remove the filter to drain accumulated water. Pumping the primer bulb clears it out for you,..... right into the motor. :facepalm:

Water separating filters work on a vacuum. Filters need to be installed down stream of any pumps (i.e. primer bulb) in the system. When installed upstream, the pressure generated from the pump forces the water out of the sediment bowl and back into the fuel system. Next stop, your carb or injectors

 

[Grub54891]

Re: water separator

.....and you don't have to remove the filter to drain accumulated water. Pumping the primer bulb clears it out for you,..... right into the motor. :facepalm:

Water separating filters work on a vacuum. Filters need to be installed down stream of any pumps (i.e. primer bulb) in the system. When installed upstream, the pressure generated from the pump forces the water out of the sediment bowl and back into the fuel system. Next stop, your carb or injectors

Uggg,ya know dingbat is right. Sometimes I wake up to early and have to much coffee. Sorry for tge misinformation.
Grub

 

[Fleetwin]

Re: water separator

Uggg,ya know dingbat is right. Sometimes I wake up to early and have to much coffee. Sorry for tge misinformation.
Grub

Don't you mean upstream!? The upstream side is vacuum, the downstream side is pressure.

All my water seperators have been mounted between the tank and the fuel pump (vaccum side).

??????

 

[metriccrescentwrench]

Re: water separator

According to the instructions that came with my Racor fuel/water separator it could be mounted either upstream or downstream of fuel pumps.

It stated that it's preferred to have the filter/separator upstream of the pump for a couple of reasons. 1) A pump might emulsify any entrained water making it less likely for water to fall to the bottom of the separator bowl. 2) Any crud coming through the line might damage the pump, having the filter/separator before the pump will help prevent that. 3) IF the filter/separator is mounted after a fuel pump you must make sure that the pump can't exceed the maximum pressure rating of the filter.

As far as whether a primer bulb is before or after the filter/separator, it doesn't matter. Water is not going to be sucked through the unit, water falls to the bottom and the outlet is at the top (except as mentioned above where a pump is churning water into tiny droplets and turning the fuel/water mixture into an emulsion - a primer bulb certainly isn't capable of that).

 

[foodfisher]

Re: water separator

Remove any doubt. Between the tank and bulb.

 

[dingbat]

Re: water separator

It stated that it's preferred to have the filter/separator upstream of the pump for a couple of reasons. 1) A pump might emulsify any entrained water making it less likely for water to fall to the bottom of the separator bowl. 2) Any crud coming through the line might damage the pump, having the filter/separator before the pump will help prevent that. 3) IF the filter/separator is mounted after a fuel pump you must make sure that the pump can't exceed the maximum pressure rating of the filter.

Ahh......the primer bulb is a "pump".

pump[SUP] 1[/SUP] (p

mp)n.1. A machine or device for raising, compressing, or transferring fluids.

Water is not going to be sucked through the unit,.

You are correct.....the water is not going to be sucked. It's going to be forced, as in pressurized, thru the filter possibly resulting in scenario #1 above. If you don't think a primer bulb can't generate a enough pressure to push water thru a filter, think again.

 

[boobie]

Re: water separator

Then what's the filter there for ?? I've always put the primer bulb on the fuel tank side of the filter and never had a problem.

 

[dingbat]

Re: water separator

......

 

[metriccrescentwrench]

Re: water separator

The dictionary definition of a pump aside, there's no way that a simple little primer bulb is going to churn and emulsify gas and water the way an electric fuel pump might (which I'm quite sure is what Racor is referring to in their diagram). Even then, Racor says that putting the pump before the filter/separator is acceptable but not ideal.

 

[dingbat]

Re: water separator

there's no way that a simple little primer bulb is going to churn and emulsify gas and water the way an electric fuel pump might .

There is no way it can happen.....very popular famous last words. Two weeks later I was boarding a plane for an all expense paid trip to China. I had to explain to the head of the plant why my design failed, causing ten of thousands of dollars in lost production. :facepalm: That was the last time I assumed anything about a third parties installation instructions.

I got to ask, why is this even an issue? How hard is it to install a vital piece equipment in the manufacturer's "preferred" location?

Nine times out of ten I have no problems at all filling the bowl with fuel after a filter change. Change filter, start motor, and let the fuel pump fill the filter. If worst comes to worst, crack a fuel line in front of the primer bulb and squeeze bulb till full.