Honda VFR750F

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VFR750P
VFR750P (police variant of VFR750F shown)
Manufacturer Honda
Production 1986-1997
Engine 750 cc liquid-cooled DOHC V4 four-stroke, carbureted

The Honda VFR750F is a sport touring motorcycle produced between 1986 and 1997. The fully-faired motorcycle featured a reliable 98 horsepower (73 kW) liquid-cooled double overhead cam (DOHC) V4 four-stroke engine. All generations of VFR750 since 1990 employ an ELF-designed single-sided rear swingarm. Also characteristic of the VFR750 (until the 2002 VFR800) was durable gear-driven cams.

The original VFR750F was introduced in 1986 as a complete redesign of the VF700/750F models in order to address some of the camshaft and bearing problems that had become associated with the first-generation Honda V4 engines, and to improve Honda's negative image concerning this engine. Compared to the VF750F, the new VFR750F featured greatly improved power output, lighter weight, a lower center of gravity, a wider front tire and a slightly longer wheelbase.

The VFR750F received many positive reviews and awards while in production, including winning the Best 750cc sport bike award from Cycle World six years in a row.[citation needed]

Although not designed as a race bike, in 1986 British racer Ron Haslam took a standard VFR750F to third place in a soaked Transatlantic Challenge race at Donnington Park, UK.

In the United States Fred Merkel piloted a VFR to victory in the 1986 AMA Superbike Series before his bike was passed to Bubba Shobert who took 3rd place in 1987, being beaten by Wayne Rainey and Kevin Schwantz. The points he earned during the 1987 season gaining him victory in the AMA Grand National. In 1988 Shobert won 3 of the 7 races to win the AMA superbike championship.

An engine race kit was available for the 1986 VFR from HRC for $4k (USD), including a titanium exhaust.

"Tariff beater" 700cc versions (VFR700F) of the first-generation bike were available alongside 750cc versions in the US market, due to the tax laws in place at the time that penalized large-displacement imported motorcycles (in order to protect the troubled Harley Davidson Motor Company).

In the Japanese domestic market there were other VFR750F variants.

  • VFR750P A police-spec model with its own distinctive model number (RC35) was restricted to 77ps (75hp) and fitted with a 5 speed gearbox, modified main stand, gear indicator, uprated alternator, crash bars, higher handlebars, and modified speedometer. This bike was not on sale to the general public.
  • VFR750K Not to be confused with the VFR750FK, this training version of the VFR750F, again with its own distinctive model number (RC37), was restricted to 77ps (75hp). The oil cooler was removed and it was fitted with a modified main stand and gear indicator. This bike was sold to the general public.


Contents

[edit] Engine

The VFR750F series all used 748cc 16-valve gear driven DOHC liquid-cooled 90° V4 engines with carburetor-based air/fuel induction; the bore/stroke remained the same for all 750 models at 70.0 x 48.6 mm (2.8 x 1.9 inches). The engine was made of cast aluminium alloy with the crankcase being divided horizontally, VFR750P and VFR750K models use slightly different crankcases with the lower casing being modified to allow for the gear position indicator in place of the neutral switch. On all the VFR750 models the gear drive for the cams was between the cylinders. Lubrication was via a wet sump with a chain-driven, dual-rotor oil pump; an oil (air) cooler was also fitted. Transmission was a 6-speed, with a constant-mesh, wet multi-plate clutch and chain drive to the rear wheel with the exception of the 5 speed VFR750P which featured a spacer in place of one of the gears.

The V4 engine has proven itself highly reliable, with few known faults. The gear-driven camshaft system removed any lingering concerns about cam-chain maintenance, which had dogged the VF-series of Honda V4 engines. Valve adjustment on first-generation VFR750Fs was by screw and locknut, which changed in 1990 to shim-under-bucket, along with the valve-clearance inspection interval (to 16,000 miles). However, RC36 engines have been known to reach well over 50,000 miles without any need to adjust the valve clearances.

Second- and third-generation VFR750Fs have notoriously suffered from failed regulators/rectifiers, likely caused by heat damage. Although Honda eventually re-designed the replacement part, such that failures of the new, finned regulator/rectifier are rare, it had become commonplace for VFR750F owners to carry spare regulator/rectifiers or even install small cooling fans to prevent reg/rec units from overheating.

[edit] Suspension

First-generation VFR750Fs sported anti-dive (adjustable on some models) on the damping-rod front 37mm forks (uprated to 41mm for 1988) and a conventional, dual-sided aluminium swingarm with a centrally located damping unit with remote hydraulic pre-load adjustment at the rear.

Second-generation models featured non-adjustable 41mm cartridge-style Showa front forks, coupled with a remotely adjustable (for pre-load) emulsion-type Showa shock absorber and the trademark single-sided swing arm. Honda soon upgraded the VFR750F's suspension to include pre-load adjustment on the forks, and damping adjustment on the shock. The bike's distinctive swing arm, derived from the ELF-designed race-bike Pro-Arm development work, has the advantage of allowing rear-wheel removal without the need to remove the drive chain or rear axle, and allows chain adjustment to be made very simply with no concerns of altering wheel alignment.

Third-generation VFR750Fs continued to use the same basic suspension components as the VFR750FN/P, though the single-sided swing arm was redesigned to reduce the weight of the earlier model.

[edit] Models

The VFR750F can be divided into three distinct "generations", with significant revisions having taken place upon the introduction of the VFR750FL in 1990 and the VFR750FR in 1994. VFR750F ceased production in 1998 with the introduction of the VFR800Fi, marketed as the "Interceptor".