Yamaha F4 Owner's Manual page 22

Specifications and requirements
EMU25280
One Star—Low Emission
The one-star label identifies engines that
meet the Air Resources Board's 2001 ex-
haust emission standards. Engines meeting
these standards have 75% lower emissions
than conventional carbureted two-stroke en-
gines. These engines are equivalent to the
U.S. EPA's 2006 standards for marine en-
gines.
EMU25290
Two Stars—Very Low Emission
The two-star label identifies engines that meet
the Air Resources Board's 2004 exhaust
emission standards. Engines meeting these
standards have 20% lower emissions than
One Star-Low-Emission engines.
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EMU25300
Three Stars—Ultra Low Emission
The three-star label identifies engines that
meet the Air Resources Board's 2008 ex-
haust emission standards. Engines meeting
these standards have 65% lower emissions
than One Star-Low-Emission engines.
EMU33861
Four Stars—Super Ultra Low Emission
The four-star label identifies engines that
ZMU01702
meet the Air Resources Board's Sterndrive
and Inboard marine engine 2009 exhaust
emission standards. Personal Watercraft and
Outboard marine engines may also comply
with these standards. Engines meeting these
standards have 90% lower emissions than
One Star-Low-Emission engines.
ZMU01703
ZMU01704
ZMU05663