"These new HPDI's have it all — reliable, dependable and
fuel efficient. And the acceleration is fantastic! Yamaha, you've done it again!"
Bruce
Richardson
Key West, Florida
Yamaha
HPDI |
Conventional
DI |
HPDI RELIABILITY
Only Yamaha HPDI outboards feature
unique internal-opening injectors, creating superior fuel atomization for improved
performance and durability. In competitive DI outboards, the fuel injectors protrude into
the combustion chamber, disrupting the fuel flow and creating the potential for carbon
buildup that could reduce performance and cause potential engine malfunction.
Only Yamaha HPDI outboards feature a
unique lower piston ring that optimizes the flow of oil to the upper piston ring, for
unmatched reliability.
Yamaha HPDI outboards use normal
spark plugs. Other DI outboards require hotter-running spark plugs that are more expensive
and can be prone to pre-ignition problems. |
HPDI INNOVATION
Yamaha starts the new millennium with a new dimension in marine fuel injection: High
Pressure Direct Injection (HPDI). Yamaha HPDI Outboards are not redesigned automotive
engines. We developed a system exclusively suited to the demanding requirements of marine
outboards. |
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How HPDI works.
Eight sophisticated engine block sensors relay vital engine operating data to the Yamaha
microcomputer, which instantly optimizes ignition timing and fuel mixture. The fuel is
drawn to the fuel pump, routed through the vapor separator, and then pressurized by the
high speed fuel pump to an incredible 700 psi. The injectors distribute the finely
atomized fuel into the cylinders, above the pistons. Yamaha's exclusive 02 sensor
continuously measures the oxygen present in the exhaust gases, enabling the computer to
deliver the precise fuel mixture to each cylinder at all times. HPDI technology is just a
hint of things to come, as Yamaha takes outboard technology into the new century.
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PRESSURE PROVIDES
INSTANT STARTS AND PRESSURE REGULATOR maintain injection pressure at a constant 700
psi.
700
PSI HIGH PRESSURE FUEL PUMP creates greater atomization of fuel for improved
combustion.
INTERNAL
OPENING FUEL INJECTORS do not protrude into combustion chamber. Nothing obstructs the
fuel flow.
COMBUSTION
CHAMBER designed to be fuel efficient at all rpm ranges, especially 2500-5500 rpm
range where fuel economy is really important.
PATENTED
O2 SENSOR enables microcomputer to control the air/fuel mixture and operating
temperature on a per cylinder basis.
NEW
76-DEGREE BLOCK DESIGN — new narrower design provides more power. |
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| Tomorrow's outboard fuel injection system is a reality today. Yamaha's HPDI
meet the Federal EPA emissions standards for 2006 — reducing emissions by 75% —
while providing the performance and fuel economy you need. It's uniquely designed to
deliver fuel economy at all rpm ranges, especially the 2500-5500 rpm range, where you
really need it. And not only does it do all this better, it does it as much as 4.5 decibels
quieter. |
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700 PSI High Pressure Fuel Pump
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