Ducati Monster Forum

Moto Board => Tech => Topic started by: koko64 on June 25, 2014, 08:26:22 PM

Title: Crankcase Breathers.
Post by: koko64 on June 25, 2014, 08:26:22 PM
Crankcase breathers seem to come in a few types. I noticed that the old alloy and newer plastic OEM parts appear very leak prone and the plastic version subject to cracking from what people say. My old M900 has the earlier alloy version and it began to leak. I changed the gasket and applied sealant and it's been fine. The reed valve appeared in good working order too.

I am leery of retro fitting the plastic oem type to older Monsters as I would like to torque them up a bit. So aftermarket types appear the go and come in colours if you like.

I'm interested in the different reed valve designs and how sturdy and effective they are.
The different aftermarket breathers come with different reed valve material ranging from special plastics to carbon to alloy. EDIT: The reed valves I thought were alloy are most likely stainless. The reed valves in my alloy stocker had a pivot hinge, but some appear to be designed to flex via thin material. I like the hinged/pivot type on first impression.

Anyone have any thoughts or experience with this?
Cheers thanks.
Title: Re: Crankcase Breathers.
Post by: Heath on June 25, 2014, 09:00:34 PM
When my plastic one started leaking on my S2R800 i replaced it with a breather from Nichols. It has the flex type reed valve. I assume it is still holding up fine but I haven't had to open it for a long time. I plan on getting one for the S4R if it starts leaking or I get some extra dough.

http://nicholssportbikes.com/products/NBREATHER.html (http://nicholssportbikes.com/products/NBREATHER.html)

You can get it from CA Cycleworks
http://ca-cycleworks.com/nmibreather (http://ca-cycleworks.com/nmibreather)

(http://img530.imageshack.us/img530/6493/breatherym9.jpg)
Title: Re: Crankcase Breathers.
Post by: koko64 on June 25, 2014, 09:14:44 PM
Thanks Heath (I always think of our late Heath Ledger when I see your posts, don't really know why).
I couldn't find it on the CCW site for the life of me, thanks for the link. That one uses the special thermo plastic reed that's supposed to be very durable. The Oberon uses carbon reeds, the SSR one seems to use alloy from their site. I am leery of something flexing a gazzilion times, so I like my old stocker. I'm just not sure which type to recommend to people when they need or want to replace that part.

Our sponsors are reliable and sell good stuff, but I'm having trouble getting my head around the flex type reed valve. Mind you, a pivot/hinge can wear and have issues also.

Edit: The part description mentions a "roll pin". Maybe this has a pivot/hinge function?
Title: Re: Crankcase Breathers.
Post by: Speeddog on June 25, 2014, 09:36:15 PM
The fiberglass reed material was very common for 2-stroke reed valves.
Quite durable in that application.
Although, they has a nice curved steel 'stopper' behind them, which helps a lot.
Title: Re: Crankcase Breathers.
Post by: koko64 on June 25, 2014, 09:42:13 PM
G'day speeddog. :)

I was wondering how they compared in application. The reed actually pivots with no resistance on my old stocker.
Title: Re: Crankcase Breathers.
Post by: Speeddog on June 25, 2014, 09:54:24 PM
Oddly enough, I've never opened an old-style stocker.

The two-stroke reed valves are like so:

(https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQwBPqY8hRuUHypXtcr3sd_hoSt0a0AMKAzewIlWHpLVJr6DE6i)

Carb flange attaches to the bottom side as shown.

That one is Yamaha style, a rubber coated aluminum body, stainless steel reeds, and steel stoppers.
With the rubber coating, the stainless would live, and the stainless reed is quite flexible and doesn't take a 'set'.
Occasionally they break off, and get sucked into the works, and then everything looks quite second-hand.

Fiberglass ones are a little less flexible, and take a bit of a 'set', so don't seal quite as well.
But they're totally digestible, a broken one gets mauled and what's left blows out the pipe.
Title: Re: Crankcase Breathers.
Post by: koko64 on June 26, 2014, 08:03:02 PM
Any thoughts on an alloy reed valve?
Title: Re: Crankcase Breathers.
Post by: Speeddog on June 27, 2014, 05:01:25 AM
An aluminum reed that flexes?

Or one that is on a hinge?
Title: Re: Crankcase Breathers.
Post by: koko64 on June 27, 2014, 05:13:34 AM
Quote from: Speeddog on June 27, 2014, 05:01:25 AM
An aluminum reed that flexes?

Or one that is on a hinge?

The SSR breather reed valve looks bolted down. The part description is "alloy filter" on the slingshot site.
Title: Re: Crankcase Breathers.
Post by: Speeddog on June 27, 2014, 05:16:15 PM
Quote from: koko64 on June 27, 2014, 05:13:34 AM
The SSR breather reed valve looks bolted down. The part description is "alloy filter" on the slingshot site.

http://www.slingshotracing.net/catalog/ducati-cnc-billet-oil-breather-p-150.html (http://www.slingshotracing.net/catalog/ducati-cnc-billet-oil-breather-p-150.html)

It looks like a stainless reed.

If it's an aluminum reed, it'll break sooner or later.
Title: Re: Crankcase Breathers.
Post by: koko64 on June 27, 2014, 05:18:18 PM
Thanks.
The alloy filter must be a mesh I guess.
Title: Re: Crankcase Breathers.
Post by: brad black on June 27, 2014, 07:49:45 PM
if the late plastic ones start leaking i remove them and goop the thread and o-ring and refit.  generally i don't like gooping o-rings, but it seems to be about the best.  plus the goop will help keep it tight.  if you can't get a spanner on it (you generally can't when it's assembled) i put a piece of thick rubber around the snout and use multigrip s(channellocks) to grip and tighten gently.  plus the hose when clamped will help hold it in place.

i don't see the need to go aftermarket personally, but that's just me.
Title: Re: Crankcase Breathers.
Post by: koko64 on June 27, 2014, 07:58:49 PM
Ever seen any cracked ones, maybe from over tightening?

I gooped my oem alloy one with a new washer. It's fine.
Title: Re: Crankcase Breathers.
Post by: brad black on June 28, 2014, 04:15:58 AM
no, don't think i've ever seen any cracked ones.  i'd go a plastic one every time.
Title: Re: Crankcase Breathers.
Post by: Rudemouthsky on June 30, 2014, 04:36:41 PM
I got this last year, it looks almost identical to the Nichols but it's Ducati brand and part #,  966019AAA.

http://www.powersportsnetwork.com/enthusiasts/catalog_item_detail.asp?catalog=3607&levelcode=25394&product=429244&cattype=&ProductCategoryCode= (http://www.powersportsnetwork.com/enthusiasts/catalog_item_detail.asp?catalog=3607&levelcode=25394&product=429244&cattype=&ProductCategoryCode=)

I run a little knock off K&N $4 filter directly attached to it, never had a leak or any misting even when wheely-ing. :) it was $100 I think on ebay.
Title: Re: Crankcase Breathers.
Post by: koko64 on June 30, 2014, 11:32:49 PM
It appears that the late model breather is sealed to the cases with an o-ring while the alloy types use an alloy crush washer. Are there any aftermarket breathers that use an o-ring between the breather and cases? I am fitting an STM type and it has no recess for an o-ring so I will use an OEM crush washer and sealant. Anyone seen any other ways they seal to the cases?

Of note is that the STM breather flows (exhales) substantially more air than the plastic oem breather, or should I say, has much less restriction. Blowing back the other way, both had similar restriction but for the oil drain back holes (maybe the oem a little more restriction). Don't know if that's of any consequence either way. I didn't 'test' an alloy oem breather.
Title: Re: Crankcase Breathers.
Post by: silas on July 04, 2014, 02:34:32 PM
I installed a red Ducabike breather on my M900 200 miles ago.   I used permatex on both sides of the alum washer.  It hasn't spewed a bit yet.  I think it was $70 , so pricey.    Original plastic one w alum band spewed a lot.
Title: Re: Crankcase Breathers.
Post by: the_Journeyman on July 06, 2014, 05:42:32 AM
I've got a $10 piece (looks like a tiny pod filter) from Advance Auto on mine.  Not a drop leaked.  Granted it's not been over or done much of a wheelie with that one, but so far it's worked fine.

JM