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Today, the marine market is dominated
by outboards, with personal watercraft being a relatively small,
and niche, market.
Emission standards have been progressively
introduced in USA since 1997, and more recently (and more stringently)
in California. Europe will introduce a next level of emission requirements
in 2005. Given that North America is the significant market for
outboards, the 'clean' outboards are now being exported to many
other parts of the worlds, even if emission requirements do no call
for 'clean engines'.
The outboard application represents unique
challenges:
· The emission cycle is heavily weighted to the higher load
operation compared to the automotive applications
· Due to the salt water environment, catalyst application
is very challenging
The outboard market offers a wide range of
engine produce mix, as the OEM's state that this is necessary due
to customer requirements. Typical product mix today is as follows:
- Small outboards:
carbureted 2-stroke and 4-stroke
- Mid range outboards: carbureted 4-stroke
and DI 2-stroke
- Higher range outboards: carbureted 4-stroke,
PFI 4-stroke and DI 2-stroke
- DI 2-stroke was
introduced into the market in 1996. Today there are two systems
being utilised, the Orbital based Air Assisted DI and the Bomardier
ETec, based on the original Ficht/OMC system.
PFI is becoming common in the larger displacement
4-stroke engines, with significant development and productionising
going into these engines to aiming to achieve similar power and
torque characteristics of the 2-stroke engines including:
- Supercharging
(Mercury Verado)
- VVT (Suzuki and Honda)
- Variable Inlet Manifolding (Suzuki)
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