Breather System
Often times people pay very little attention to venting the crankcase pressure.
If the pressure in the crankcase is not allowed to escape all kinds of problems can
occur. You can develop oil leaks from the gasket or seals, you can have oil build up
in the valve cover, but most importantly you may loose power.
I have often seen people use a tiny 1/4" hose.  I have also seen people use big
rubber hoses that when stuck into the hole in the valve cover squish down to about
a 1/4 inch inside diameter. I have often seen the hose taped together and either
burnt by the exhaust or damaged by the chain.
This breather system uses a 1/2" thin wall steel tube and 1/2" id rubber hose to the
catch tank.  It provides the lowest crank case pressure possible. The catch tank is
mounted on the rear bearing hanger by two of the bearing bolts. Notice how short
and directly the hose goes to the catch tank.  
The hose can't get caught in the chain or burnt on the exhaust.
It really works great.

PRICE $39.95    WKA Legal
The catch tank is painted yellow and this one has clear hose on it so you
can see it better.
On some oval chassis you may have to bend the steel mounting plate
slightly for tire clearance.
Briggs Breather Bypass System
Price $39.95
The breather bypass system helps keep oil
from building up in the valve cover and thus
starving the bottom end for oil. If you starve the
bottom end for oil you may seize the rod to the
crank and then destroy the engine.
Faster Motors Breather bypass system .
The fitting for the side cover is better since it has a large Ferrel to keep the hose from slipping
off. It also has a much more robust  braided hose. The valve cover fitting can either be welded
in place or use a bracket to bolt it to the side of the valve cover.
No wimpy grommet that can tear or come out of the valve cover. Price $39.95
Welded fitting
Bolt on fitting