Service Manual

7-10 CAMSHAFT/CRANKSHAFT
Breather
The function of the breather is to create a negative pressure in the crankcase which prevents oil from
being forced out of the engine through the piston rings, oil seals or gaskets. A sealed-type crankcase
emission control system is used to prevent blow-by gases from emitting in the air. The blow-by gases
are led to the breather chamber through the crankcase and camshaft. Then, it is drawn into the clean
side of the air cleaner through the cylinder head and hose and mixed with the clean air flow, and
subsequently comes into the combustion chamber through the carburetor and inlet manifold.
Oil is primarily separated from the gases while passing through the inside of the rocker chamber from
the crankcase, and secondly separated from the gases in the breather chamber, and then returned
back to the crankcase cover.
FX Models