crank case breather

[Hippysmack]

The hard part about this subject is that the whole pressure system has to be taken into account at the same time.
We also speak of blowby as in compression getting past the rings and into the crankcase.
But that can also work in reverse especially on engines with worn rings which is another factor.

I kind of think of it more of a closed system with an intake air leak (blowby).
You are right, the changes are small when things are going good.
And truthfully, this is all a talking point until problems occur.
As with the op with oil puking out the oil tank;
Knowing what should be happening inside sometimes clues to why it happened and how to diagnose and fix it.
I believe you can pull up too much oil in suspension which is compounded on the next cycle and it gets ugly after that.
So as long as everything is percolating, changes are small.

I believe it is 91-03 engines with the largest splash holes in the cam wall (91-99 in particular).

They blocked those off with the piston squirters in 04 which bottled up the CC leaving the pinion bearing as the only vent port to the cam chest.
They closed off the top end otherwise including moving the heads drains to the cam chest.
But they also have the flywheels with the cups cut into the ends for the crank sensor.
So the wheels are no longer slick on the end which is bound to pick up more windage.
Think about it, they didn't have to cup the wheels. They could have installed a trigger on the face with a horizontal pickup.

I don't believe upstroke picks up raw oil but rather oil mist.
The wheels can pick up mist from the sump which compounds around the wheels which is the reason for windage trays.
The fluctuations pulse air/oil mist that is picked up by all the moving parts.
So upstroke play does a part in lubrication however slight.

On a separate note, I am working on a homemade slack tube.
Made the fitting and got a hose. Just have make a backplate.

[60Gunner]

Plugged breather/lines or umbrellas letting air back in as much as they let air out is a bigger issue than a lot of people seem to realize. They location of the umbrellas in the heads compounds this problem not only by a higher failure rate due to heat warping them but also by the fact they're isolated. Out of sight, out of mind so to speak. The fact the rocker covers/boxes need to be removed to service breathers is a piss poor design plain and simple. Don't underestimate the importance of a properly working breather system.
As for the cheaper knock offs of the Hayden Krankvent, how long will it work properly? I wouldn't use one that didnt come apart to clean if necessary just to save a few bucks. Or one that doesn't close properly after some use and wear and allows air in. They might work fine...for awhile. Get what you pay for.

[Highly-Dangerous]

Originally Posted by trucker2800

thanks but i checked the oil before i ride but have not put any in since I bought it but will run it and check, previous owner may have over filled it thanks to all of you for the feed back.

.... and???