THS - The Honda Shop Megastore

Honda"s completely-redesigned BF40 and BF50 EFI four-strokeoutboard engines have arrived!

Retaining their class-leading lightweight and compact styling,the new engines are enhanced with electronic fuel injection,Honda"s revolutionary Boosted Low Speed Torque (BLAST") air/fuel ratio and ignition-timing technology, and Lean Burn Control to deliver powerful start-up and acceleration together with outstanding fuel economy during cruising.

BLAST", along with a newly-designed, streamlined gear case and other improvements, contributes to greater acceleration and a higher top speed, while Lean Burn Control results in a 22% improvement in fuel economy over the previous models.

Battery charging capacity has also been increased to 17amps " over 1.7 times that of the previous BF40 and BF50.

The new models are compatible with Honda"s latest general purpose engine diagnostic system (Dr H) and also feature a new one-touch plastic cap, which permits easy inspection of anode wear inside the engine, for significantly improved ease of maintenance.

Consistently leading the world in environmental performance, Honda has also managed to reduce noise levels by 1.0dB over previous models through such improvements as a longer exhaust pipe and an optimised rib design inside the upper portion of the extension case.

Both models exhibit outstanding environmental performance and exceed: 2008 CARB emissions standards " the most stringent in the world; US EPA standards for 2006; and domestic Japanese voluntary regulations.

As is the case with every other model in Honda"s outboard engine range, the new BF40 and BF50 also achieve the Outboard Engine Distributors Association"s (OEDA) three-star rating for ultra low emissions.

Features

• Lightest and most compact outboard engine it its class!
• Long branch plastic inlet manifold
• Small electrical parts (O2 sensor, etc)
• High output
• Large bore throttle body
• Adoption of BLAST"Excellent fuel economy and ultra low emissions
• PGM-FI and Lean Burn Control
• Full complement of accessories
• Long tiller handle with angle adjustment functionFour-bulb warning lamp (tiller model only)
• Can be connected to Honda"s new diagnostic unit (Dr H)
• Lifting the cowl of Honda"s new BF40/50 reveals an inline three-cylinder, six-valve, 808cc (0.8L), single over-head cam (SOHC) marine engine"

Honda"s revolutionary Boosted Low Speed Torque (BLAST") air/fuel ratio and ignition-timing technology was first employed in Honda"s BF75/90, released in September 2006.

BLAST" utilises MBT " Minimum advance for Best Torque " trace control, which is based on basic engine ignition timing theory. By linking the ignition timing control of the engine to the air/fuel ratio, it sets the optimum timing via computer control.

BLAST" traces the air/fuel ratio that results in the maximum torque for each engine revolution, while simultaneously tracing the maximum knock limit ignition timing that can be obtained using a rich air/fuel ratio in the full throttle zone, and advances the ignition timing to the limit (27"), in order to produce greater torque.

This boost in horsepower and torque at low rpm contributes to strong hole shot performance to get the hull up on plane quickly!

BLAST" ensures strong acceleration to get boats on the plane quicker!

The new BF40/50 incorporates Lean Burn Control technology, which allows combustion to operate on a leaner air/fuel ratio (14.7 to 1 ~ 18.0 to 1) than stoichiometric air/fuel (14.7 to 1).

The engines each utilise an O2 sensor. Together with the ECU the sensor precisely controls the air/fuel mixture for the best fuel economy at cruise setting.

The mode in which Lean Burn Control is used during cruising to achieve higher fuel economy is referred to as ECOmo (Economy Controlled Motor).

Programmed Fuel Injection (PGM-FI) And Return-Less Fuel Piping

Honda"s PGM-FI is a sequential multi-port electronic fuel injection (EFI) system. PGM-FI results in easy starts and instant throttle response.

The pressure regulator, which was installed on the delivery pipe of the conventional PGM-FI model, was integrated with the vapour separator, thus simplifying the high-pressure fuel piping.

In the new BF40/50, the return fuel is returned to the highpressure pump case, thus reducing air inclusion during abrupt acceleration

High-Performance Gear Case

The BF40/50 features an all-new lower unit design to create a high-performance gear case, which aids in reducing spray and water resistance, educing hull porpoise and drag, thus increasing acceleration, top speed and fuel economy.

The strength of each part has been increased, resulting in greater reliability, while the trim tab anode has been removed and anode metal installed on both sides.

A 2.08:1 gear ratio allows for optimal propeller selection for overall performance.

*The drain bolt and check bolt on the gear case have been relocated to the port side to facilitate ease of maintenance.

Tiller Handle Adjustment Mechanism

The new BF40/50 uses an adjustment mechanism that enables the handle height to be selected by changing the mounting direction of the height adjustment block, depending on the seating position in the boat or the preference of the person driving the boat.

The angle of the steering handle can be set to 7", 13", or 21"

High-Output Alternator

The new alternator is equipped with a multi-pole AC generator (ACG), featuring more generating coils than the previous model BF40/50. The ACG is located on the cylinder block and connected coaxially to the crankshaft.

A different type of regulator is used, resulting in greater compactness and the highest battery-charging output in its class!

Improved Flywheel Assemly

The flywheel of the previous BF40/50 model was clamped with four bolts. In contrast, the crankshaft of the new BF40/50 has been changed to a tapered one and the flywheel is secured with a single nut, facilitating easy disassembly and reassembly.

New Inlet Manifold And Large-Bore Throttle Body

The new, lightweight plastic inlet manifold consists of an integrated chamber extending from the throttle body to a midway point, as well as dedicated passages which branch-off from this point to the engine"s three cylinders.

This results in increased output from low-speed to high-speed as well as reduced weight.

Cooling System

Cooling water enters from the water screens on both sides of the gear case as well as the water bottom screen. It"s then drawn up by the water pump and fed through the water tube and oil case to the primary gear case.

The cooling water that has passed through the primary gear case flows into the cylinder head and the cylinder block. The cylinder block contains a thermostat (open valve temperature: 60"C; fully open temperature: 70"C) which maintains the temperature inside the water jacket at the optimum value.

The cooling water that has cooled the vapour separator is discharged from the telltale.