crankcase breather filter

[Guest]

In all the discussion about pods installation no mention was made of the need to install a crankcase breather filter as well. Are these somehow plugged into the breather hose and secured somehow?

[Steve]

I have seen two methods used.
1. Run a longer piece of hose back, then down to where the other drain hoses are. This is much like cars used to be before implementation of the PCV systems.
2. Go to the tuner section of your auto parts store and get a breather filter. Looks like a little pod filter for the carbs. These are usually available in a selection of colors.

.

[Tarbash 27]

or add a catch can so you dont have oil spewing all over. The breather filter will spit out oil.

[Flaggo60]

So, as I understand it, in the stock airbox setup the breather hose goes back into the airbox and then the airbox has a drainage hose out the bottom. Then in the case of the crankcase breather filter addition where the airbox is removed, some of the excess crankcase oil would come into contact with this aftermarket filter. Why is a filter suggested and available-wouldn't it plug with oil after a period of time?

Environmental concerns seem to be ignored in either approach as they probably were not in effect in 1981. Therefore, why not just have the oil drip out the hose, a task formerly done the same way out of the airbox? Or is it a two way thing-oil can drip out but a vacuum can suck air back up the tube and therefore a filter might be helpful?

[chef1366]

Shoot in that case just run it so it drips on your chain.
If you have one.

[Larry D]

I'm not a motor guy, but I've read in these forums, that it is indeed a "breather" hose. It expells gases from the engine and also intakes a certain amount. Therefore the need for the filter, so road grundge, grime, dusty bits, etc.. doesn't get into the engine.

I forget what I was searching when I ran across that...exhaust something or other, perhaps.....

[Flaggo60]

Shoot in that case just run it so it drips on your chain.
If you have one.

No-its shaft drive-a 650G.

[Flaggo60]

........I'm not a motor guy, but I've read in these forums, that it is indeed a "breather" hose. It expells gases from the engine and also intakes a certain amount. Therefore the need for the filter, so road grundge, grime, dusty bits, etc.. doesn't get into the engine....

That's my understanding as well. I can see the need to filter incoming air that will eventually reach the engine, but I can't see how the drips of oil going out wouldn't contaminate the added-on crankcase breather filter, unless it has a drain built into it for that purpose-I've never seen one up close.

[Tarbash 27]

You dont really need a filter on the breather hose. Theres already a metal screen in the valvecover. I think the filter just looks better than a hose venting to the atmosphere.

[Steve]

I think the filter just looks better than a hose venting to the atmosphere.

That's why I just ran a longer hose down to below the swingarm on my son's 650L.
Already had the hose, and I'm too frugal (cheap) to spring for a fancy little filter.

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[Flaggo60]

From the thoughts expressed here I'm beginning to believe that the add-on crankcase filter is a bit of a doodad that may clog up and interfere with the escape of the few drips of oil. However, the air that is drawn through the tube and into the crankcase would not be filtered, whereas in an airbox situation it would be.

The question now arises as to how much oil out and how much air back in is involved. GS machines are known for losing some oil between changes, even when relatively new. Does this oil pass by the rings and/or valve guides, or does a fair bit of it escape from the crankcase vent, I wonder.

[Tarbash 27]

Id say you will probably always have gases being vented out of the breather rather than air being sucked in. The blow by from the combustion chamber build's pressure in the crankcase. Therefore you will always have the gasses being vented out of the motor.

[Shaughn]

Steve's #2 option is the way I went, got this guy for $6 at a VIP Auto store.

http://www.autozone.com/selectedZip,01609/initialAction,accessoryProductDetail/initialR,1023443/shopping/selectZip.htm

[chuckycheese]

Not worth worrying about!!

As an old HD guy, I think the best thing to do is route the tube where it makes the least amount of mess (almost zero) and forget about it...I don't think the bike will last long enough to where anything sucked in will make even the slightest bit of difference. I think those little filters you can put on are a gooey, gimmicky mess that won't make a single bit of difference in the life of your engine (until they get clogged up with road grit..which they will, if they're on the underside).

[Flaggo60]

...........I think those little filters you can put on are a gooey, gimmicky mess that won't make a single bit of difference in the life of your engine (until they get clogged up with road grit..which they will, if they're on the underside).

That's what I was thinking but you said it better.

I think that tube is going to go where the airbox drain would have been and have done with it.