Crankcase breather....fact or myth?

[trip]

I've been reading on other forums that it is considered a design flaw that Kawasaki routed the crankcase breather into the air filtering system. And, I did the search here in the Garage for past discussion conceerning this subject.

I recently got back from a 2000 mile trip and found my oil level down a bit. Also found a small amount of oil in the bottom of the right side air filtering system.

So, should I?......Shouldn't I????? What's the concensus of past discussions?

[blowndodge]

Were you driving extra fast Trip? For emissions the breather is sent to the intake system to burn the fumes from the crankcase. If your getting oil under the right side cover you might have a pinched breather hose causing a spike in pressure. Check to make sure that the hose is not folded nor bent at a weird angle as to be pinched. You can re-route the hose up higher and put a filter on it but that really shouldn't be necessary.

Most vehicles have been designed this way for decades, Trip. In really hot weather or under hard running you'll get more oil coming up the tube, and that is very typical. It's a matter of smog control that the crankcase fumes must get burned off somehow, and that's how.

However, that tube does make a huge loop over the front head, and it's pretty easy to re-route that hose up under the gooseneck and locate a small breather filter there. I haven't done that, and I don't know if it will reduce oil consumption, but I suspect it would. Of course you'll be violating Federal Laws, so don't say that I recommended this. ;)

[trip]

Thanks BD and CaddQ for responding. Yes, I did run extra fast on the recent Big Bend trip. Parts of I-10 here in Texas have a posted speed limit of 80mph, so it was constant running at 3500rpm or higher for an hour and a half at a time. I always check my oil level when on trips. Didn't notice anything unusual until I got home and noticed the oil level down just a little bit.

Several of the other Classics that are older with more miles had to have oil added while on the trip. Just wanted to make sure I wasn't doing any damage to my engine due to a design flaw.

Thanks,
Trip

[blowndodge]

It's those blasted lowers!!!!!! What did I warn you about???? You'll be haulin' ass all the time!!!! SLOW DOWN!!!!! LOL!!!

[ringadingh]

I would guess the oil vapor sort of condenses a bit in the breather and thats why you see it. On high speed rides your oil pressure is at its maximum, whereas combined or city driving its a little lower, and doesn't build up the vapors as quickly.

[gshep]

Like caddmann said most engines have been designed this way for a while. One thing, don't overfill the oil. I did this on my Kawa Mule and the excess oil wound up in the air filter, clogging everything up. Cost me a new filter, so I'm carefull with the Nomad.

Shep

[trip]

Originally Posted by Blowndodge "Darksider"

It's those blasted lowers!!!!!! What did I warn you about???? You'll be haulin' ass all the time!!!! SLOW DOWN!!!!! LOL!!!

Hmmm...didn't put the lowers on until last week....

[macmac]

There is a couple easy things to do. One is buy a filter for a car cheap, made for these breathers. This usually fits a car air cleaner can, with a big sliding "U" shape clip.

You would pull out the fluff and stuff a little in the breather hose, adding 2 cotter pins before and after the fuzz.. This will slow down the breather, but not stop it.

Another thing you could do is make a flame arrestor, and maybe for that, you would go to Volvo and buy one. This is a coil of flat wire, with little bumps in it so it woun't coil as tight as a light element. Once more you want it to be where you put it, so a cotter pin before and after in the hose would be called for.

My 84 Volvo 240/245 with a BF 21 FT engine has one..flame trap that is... The breater vents out more than it draws air in, but it does work both ways. More or less the filters we add on get nasty faster, and I see is as keeping out mud dobbers more than anything else.

if you get serious about the breather with going by a filter set up, then maybe a can with a baffel to collect the oil fumes as oil, which can be drained out a times would be more showey and more in order.

[rewindgy]

My little 800 Drifter has a small bottle to catch the slight over flow. I have to empty it about every 3 - 4th oil change. It's ugly as heck but it does the job. I tried painting it black so it doesn't stick out like a sore thumb but the paint peels off then it really looks a fright!

[mcdaddy]

<blockquote>Of course you'll be violating Federal Laws, so don't say that I recommended this</blockquote>

So is debaffling. And probably a lot more of the mods many of <s>us</s> you ::) have done to (y)our bikes.

Shush up McDaddy! You wanna jinx this place?