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This four cycle Lauson has my brain striving for more good brain cells.
The parts diagrams only shows the crankcase breather as an assembly,
and no hint of what’s inside of it.
At first I was just thinking it was a “snorkel” up above the crankcase a ways
so oil wouldn’t blow out the breather hole, so I blew compressed air through
it to check for pluggage. Air came out. Hopefully I didn’t damage it.
Then I got to thinking about the old automobile’s PCV (positive crankcase ventillation)
valves, that were actual a check valve.
When breathing through the small breather hole, air goes both ways, but sounds different
and you can hear a faint click as well.
Perhaps I should have been breathing through the big hole where it bolts on the
crankcase, but it tasted bad enough as it was!Anyone know how the breather is suppose to function, or the proper way to test it,
if it’s even necessary?
If worse comes to worse, there’s an expansion plug staked in a hole in one end, that
I could try to remove for a look see.
As dirty and oily as the engine was, I have to wonder about it!Does the crankcase need to ventilate when the pistons are going “Up” and
well as down? Perhaps the breather is designed for different flow rates depending
on which was the pistons are going, i.e., breaking vacuum in the crankcase
probably wouldn’t need as much flow through the valve as expelling the
air in the crankcase when the pistons are going down?
Okay, brain needs a break!
Prepare to be boarded!
Valve chamber on a B & S Model N, like the first engine I ever worked on, in 1954. Breather is the device held down by a spring under the stud. It basically is just a disk in a cage.
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