WM 90 Theory of Operation
wc_tx000388gb.fm 31
WM 90 engines use a diaphragm-type carbu-
retor.
The air cleaner is a heavy-duty three-stage
type with cyclonic precleaner.
An automatic decompression mechanism (a),
that opens the exhaust valve before the piston
reaches maximum compression, is assembled
on the camshaft for easy starting. During
engine operation the decompression system is
overpowered by centrifugal force and com-
pression is fully utilized to produce power.
Component Illustration Component Description
wc_gr001881
wc_gr002032
wc_gr001883
a