Breather

[pear0]

I got this breather with some stuff that came with a project bike. Seems to work just fine and I think looks better than a piece of tubing.
I have been looking for another on the Net and have been unable to find one that I would like to have for different project single.
Any leads or comments appreciated. TomA

http://pic80.picturetrail.com/VOL2128/1 ... 650407.jpg

[halfpast]

My breather connects to the airbox (68 Monza 250).

What kind of bike is this?

[pear0]

Bike is a 250 that was a butchered scrambler and is now a cafe racer. TomA

http://pic80.picturetrail.com/VOL2128/1 ... 988971.jpg

















bike is a 250

[JimF]

I've never seen one like that. I would venture to guess it is a complete custom one-of-a-kind.

TGA (http://www.tga.co.uk/shop/) used to sell a cool looking aluminum catch tank that you could connect the breather to. Sadly I don't see it on their site anymore. It was akin to a thick big beer can with a few spigots and drain plug that you could vent a breather hose into rather than just dump any mist on your tire.

Jim

[Jordan]

I'd be concerned that Tom's breather would not keep out rain water.
An added cap could fix that though? And maybe a short pipe venting below the swing arm, to keep things cleaner?

[amartina75]

That is from an Aermacchi Sprint. They are supposed to use a pipe like the Ducati ones. Only difference is they have a plastic piece inside that turns the air twice to catch oil. Keeps oil from traveling up the pipe. Slightly better then the Ducati ones for design I guess. I have one I thought about hollowing out and putting a PCV valve in but decided against it.

[Rick]

Tom,
I don't click on unknown links, so I haven't seen the breather, but a labyrinth style breather, like the unit from the bevel twins, may be an improvement from stock. The breather thread isn't the same on the single and twin engines, so you'd need some sort of adapter, or it may not be difficult to modify the stock unit with a labyrinth. I've never liked the idea of a long, ugly tube spraying oil mist on the rear tire.
I could take some pictures of a twin breather disassembled if you'd like to see what's in there.
Rick

[Rick]

The labyrinth style breather is just a stack of semi-circles spaced out on a shaft.

labyrinth breather.jpg

I've seen sintered bronze pneumatic valve exhaust silencers used also- Grainger has them, this photo is from Automation Direct.

pneumatic valve exhaust silencers.jpg

[Dave450]

Pear0 - the later singles had a flap valve breather which was fitted to the right hand side cover. It worked well for many years with me, but I have now fitted a one way reed valve breather which is an after-market part for Yamaha XS650s. Quite a few people have also used them with success on Norton Commandos. An efficient one-way valve is a good way to keep oil inside the engine, where it belongs. You will need to get some hose and reduce the pipe size down a bit, but a customised engine breather system is very do-able, especially with the narrow case bikes like you have, because you have more room. What you would do is fit the breather in line with the hose from the back of the engine and mount it neatly somewhere and then have the exit pipe from the one way breather go to a catch bottle - if necessary. I haven't needed to use a catch bottle (yet). If you want more details and photos, I can post them.

Rick - Never saw the inside of the Ducati twin labyrinth breather before. Thanks for posting.

Dave

[amartina75]

image.png

This could be used on a single with a little work. it looks small enough not to look too out of place. I think I'd try to find a cheaper used one not nos.