Crankcase breather pros and cons?

[scduc]

I also went the way of the TPO kit and after installing it, I noticed that something just wasn't right with the performance. She stuttered every now and then. I went back to the stock config, and the issue went away. Now, I have been told with the FI models, some tuning may be needed, so when I have the exhaust done, I will try it again. I had this done with my 00' 750, and never had a problem.

[Howie]

If the filter is mounted directly on the valve, like most I've seen, where will a burp go? Into the filter, clogging it or through the filter making a mess? (tire?)

Not a matter of will, could make a mess.  If you don't suffer excessive blowby, overfill the oil or wheelie down the block all will be fine.  As far as the filter clogging, unlikely as long as you clean it every now and then.

[GAAN]

Would there be any issue with running the hose straight from the breather valve to the airbox and bypass the tank under the seat?

[Howie]

Would there be any issue with running the hose straight from the breather valve to the airbox and bypass the tank under the seat?

Part of the breather box's job is to separate liquid from vapor.  The other is to supply ample volume.

[ducatiz]

Would there be any issue with running the hose straight from the breather valve to the airbox and bypass the tank under the seat?

This is how it is done on older bikes and there isn't THAT much problem, however hose length and breather connection might play into that.   The hose on my Pantah 650 engines is factory and is about 2 ft long.  The Pantahs used a different breather too -- which is compatible with the later models -- that is completely flat on the engine. 

[GAAN]

well I got curious and cut the tank open

I can recreate the same function inside the airbox

I think...hope

[Javamoose]

You're correct.

So, if it's just an open baffled tank (and you wanted to keep the can, but dress it up, smaller, etc), couldn't you just use a nice looking billet overflow tank?  Like this:


Replace the drain fitting with another hose-barb fitting?  Mounted with the IN port at the bottom, the oil (if it burped) shouldn't get sucked up and eventually would drain back into the case...

[RAT900]

My old Carb'd 96 M900 did NOT benefit from the TPO setup...

there was a noticeable drop-off and I went back to the stock system inside of 2 days and the bike went back to running better....

I don't know how the balance of positive and negative pressure created in the crankcase and the intake air box respectively work to improve things as a system...but they do

I have not bothered dicking around with the set-up on my 02 900ie bike....

but I would welcome a decent aftermarket canister that would free-up some space and give me some options for getting fresh air to the rectifier

I would think the input and output hose fittings would need to be the same O.D. as the stock set-up

I would jump on something like that if one came along

[GAAN]

I dunno about the hoses needing to be the same size, the hole underneath the reed valve in the breather is teeny tiny

[ducatiz]

I bet you could find one of those old scool pcv filters with a hose barb. They used to poke thru a hole in the air cleaner holder with a clip to hold it securely. You'd need a new hole in your air cleaner.  Ill post a link.  They put them outside the filter tho which might be hard esp if you've trashed the cover

[scott_araujo]

This is how it is done on older bikes and there isn't THAT much problem, however hose length and breather connection might play into that.   The hose on my Pantah 650 engines is factory and is about 2 ft long.  The Pantahs used a different breather too -- which is compatible with the later models -- that is completely flat on the engine. 

Just running some more hose should help some.  It's unlikely to completely fill with oil which means it will just burp a little bit up which should drain down on its own.  A smaller baffle inside the air box like Mother is planning would likely work with a long, large diameter line run to it.  Probably really easy to solder something together from sheet copper.  Now you've got me thinking...

Scott

[ducatiz]

This is what I was referring to:

http://www.aaaaautomotive.com/Shop/Control/Product/fp/SFV/32785/vpid/6720760/vpcsid/0/rid/134382

The whole thing sits INSIDE the air cleaner box, with the spigot/barbed bit coming out the side for connection to a hose.

THe clip goes on the spigot to hold it in place.

VERY common on 1970's American cars..

[Howie]

This is what I was referring to:
http://www.aaaaautomotive.com/Shop/Control/Product/fp/SFV/32785/vpid/6720760/vpcsid/0/rid/134382

The whole thing sits INSIDE the air cleaner box, with the spigot/barbed bit coming out the side for connection to a hose.

THe clip goes on the spigot to hold it in place.

VERY common on 1970's American cars..

Most cars with Positive Crankcase Ventilation allow air into the crankcase as well as blowby gasses out.  Typical is filtered air enters the cranckase through a device like in your link and blowby exits the crankcase through a hose to the intake manifold controlled by a PCV valve or a small orifice.  Most cars run with negative pressure (vacuum) so a provision is needed for fresh air.  Ducatis need a big area to collect the (hopefully) slight positive pressure, which is why the breather box is there, just check out the sized of a Corsa breather box. 

[corey]

have had my filter on for 3500 miles, not a single drop out of it. no performance drops or anything...

[ducatiz]

 

Most cars with Positive Crankcase Ventilation allow air into the crankcase as well as blowby gasses out.  Typical is filtered air enters the cranckase through a device like in your link and blowby exits the crankcase through a hose to the intake manifold controlled by a PCV valve or a small orifice.  Most cars run with negative pressure (vacuum) so a provision is needed for fresh air.  Ducatis need a big area to collect the (hopefully) slight positive pressure, which is why the breather box is there, just check out the sized of a Corsa breather box. 

I am pretty sure that filter is for stuff coming out of the engine, not going in.  The filter protects the air filter for the carb from getting spoiled with oil.  At least that's how it was on my old Ford.

Direct hose from the valve cover goes to that air filter thingy.  Later models had a reed valve type setup like you describe, IIRC.