Vacuum non return valve

[Rossiroadrunner]

How is this used and where do you connect the outlet if it isn't going to the air filter?
I presume you'll still get some oil mist from it.
Thanks

[namster]

On my Lomax it went to a "catch tank" which was basically a sports water bottle in a bike frame mount bolted to the bulkhead. Over the 7 years of running it, it probably only got about a cm of oil in bottom of the bottle.

on my Pembleton it's unconnected and just vents to atmosphere and found very little oil spatter on the surrounding components - although I'm not 100% happy with this and will probably do a similar arrangement to my Lomax when I can be bothered.

[llanigraham]

Mine vents to the atmosphere via an aluminium "thing" and I've got no oil mist staining anywhere.

[Rossiroadrunner]

Thanks chaps, i'm a bit wiser now... Need to order the valve now.

[howardjs]

Hi, Had mine going to an additional air filter but decided that this was not very environmentally friendly, so now it goes to a catch tank with small filter on top. No mist around the filter and so far no oil to be seen in the site level tube.

The very nicely machined aluminium catch tank came from Ebay for about £18

DSCF6973.JPG (152.78 KiB) Viewed 12514 times

Howard

[llanigraham]

Howard,
What is the aluminium "thing" close to the engine in the inlet pipe supposed to do?
I've got the same thing on mine, but it seems to have nothing inside it; just an open pipe.

[howardjs]

Hi, The "thing" is a crankcase breather vent non return valve. It should have a leaf spring and a retaining plate inside it.
It replaces (or works with) the rubber sleeve non return valve inside the oil separator / filler vent unit.
Non return valves which are not working properly are a common cause of engine oil leaks due to a build up of pressure in the crankcase.
Howard

[llanigraham]

Mine has obviously been "modified" then, as there is nothing inside it at all. It's just an open pipe.

[stevep]

Hi all
The aluminium crankcase breather is called a foo foo after the sound it makes on engines with a heavy flywheel when slowing down after switching off (named by my wife Janet)
I have been making them for over 15 years now and sell thro the club and Ecas , club price is only at cost !
The valve is made from spring steel and should be held in with a small m3 screw which means it can be cleaned if required, I have had the original on my engine for over 17 years with no reason to take it apart only a wash off with cleaner every couple of services periods . If the spring is missing nothing is helping with the crankcase pressure and you will blow the crankcase seals if the engine run for to long like it.
A none return breather is required on an opposed twin to maintain the crankase vacume which will help the oil seals from leaking , the citreon original is a service item , because it is made with a rubber inner which goes hard and looses its effectiveness
The foo foo was made to make this citeroen part not needed it was designed to be fitted in the outlet side tube from the original .
And has been fitted to over 2000 engines that I aware of, they are also now being fitted to old Morgan V twins,
I now have one on my moto guzzi engine Lomax .

I do take the outlet to a catch tank but with a well run in engine you will get very little oil residue

[llanigraham]

Steve.
As said, mine has nothing inside it, so has obviously been "modified" at some time.
Do you have a link to where I can get one, please?