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NR (NR750; RC40) Model Info



The following paragraphs describe, in Honda's own words1, the design philosophy [we think...] behind the NR:

Object of Development
Unlike conventional sports motorcycles, that used to pursue exclusively a dynamic run, NR750 was born as a new road sports realizing a perfect balance between the antagonistic characteristics of dynamic power feeling and elegance, with the "I want to feel the emotion of riding a motorcycle!" development concept applicable not only when you are giving it a dynamic run, but also when you are enjoying the gliding feeling of the controls and when you are performing ordinary throttle work.

Output Characteristics
Featuring oval pistons with non-round shape challenging the "round shape" common sense of pistons, that seemed to be perennially valid ever since the invention of the reciprocating internal combustion engine, its performance has improved by a leap, and it realizes easy handling, high-ceiling performance and crispy output characteristics that can be expressed as "Dynamism & Elegance", by giving full play to the merits of the oval piston engine.

Rider Comfort
A comfortable and thrilling riding space is realized from ordinary run in street areas to high speed cruising on highways.

Design of a New Road Sports Bike
An original atmosphere, individuality and sense of value was created by selecting "Assertion of its Presence" as a theme, for the NR750 to stand out for its striking presence even when surrounded by hundreds of other motorcycles.

Running Characteristics
An elegant feeling of quality absent in conventional motorcycles is realized by surpassing the old concept of absolute performance expressed in terms of mere dynamism. In other words, a compromise is found between technical data and feeling by introducing the concept of elegance in addition to the old trend based exclusively on performance and technical data pursuing exclusively dynamism. Thus, every behavioral detail of the motorcycle body is characterized by moderation, and running characteristics expressed in terms of "Enjoying and Feeling Pleasure and Satisfaction with the Controls" when running straight stretches, negotiating curves and braking at every speed range are realized as an extension of that moderation.

The fairing shape was designed after repeated computer analysis and wind tunnel experiements, for ground-gripping feeling of the tiresto remain upchanged up to the high-speed range, by taking into consideration not only the reduction of the wind pressure working on the upper part of the rider's body but also the subtle changes in the wind when the motorcyle changes its direction. Aerodynamic performance characterized by "zero" total lift force is realized as a result.

Visibility, Noticeability (Preventative Safety)
The presence of motorcycles is not so noticeable comparing with cars because they have smaller surface area. Making motorcycles noticeable within the road traffic is an important theme. Improved visibility and noticeability are realized through the adoption of flourescent red-painted looks with brightness surpassing by far the conventional colors, as well as a projector-unified headlight securing sufficient front illumination without glaring other vehicles.


There was just the one model, the "N", built at Honda's Hamamatsu factory during 1992. French-spec models were sufficiently different from the others to require a different vehicle description code (RC41 vs. RC40), and in order to achieve the French-market 100bhp limitation, RC41s feature different profile camshafts and different PGM-FI units. Swiss and Austrian models featured additional emissions control equipment, notably an air injection system similar to (but not so named) the PAIR system found on many other Hondas. Finally, UK-spec models also featured a button to change the LCD display from MPH to KPH (presumably for those long, continental sport-touring trips...)

The following table details the serial, engine and throttle body numbers for the [~300-unit]2 NR production run:

Year Code Region Beg. Engine #s End. Engine #s Beg. Frame #s End. Frame #s Throttle Body ID #s
1992 N Austria 5000001 [5000005]2 2000032 [2000037]2 GQ11A-B
1992 N European Direct (Belgium, Holland, Italy, Portugal) 2000032 [2000105]2 2000019 [2000117]2 GQ10A-B
1992 N France (RC41) 2000001 [2000022]2 2000001 [2000020]2 GQ10A-B
1992 N Germany 2000036 [2000116]2 2000025 [2000104]2 GQ10A-B
1992 N Japan
1992 N Spain 2000037 [2000118]2 0M000001 [0M000006]2 GQ10A-B
1992 N Switzerland 2000039 [2000108]2 2000027 [2000094]2 GQ11A-B
1992 N U.K. 2000035 [2000110]2 2000024 [2000096]2 GQ10A-B


Item Specifications
Dimensions: Overall length 2,150mm (84.6 in.)
Overall width 700mm (27.6 in.)
Overall height 1,090mm (42.9in.)
Wheelbase 1,435mm (56.5 in.)
Seat height 785mm (30.9 in.)
Footpeg height 360mm (14.2 in.)
Ground clearance 130mm (5.1 in.)
Dry weight 223.0kg (491.6 lb.)
Curb weight 244.0kg (537.9 lb.)
Maximum weight capacity 115.0kg (253.5 lb.)
Frame: Frame type Triple-square section twin-tube
Front suspension Telescopic; inverted type
Front wheel travel 120mm (4.7 in.)
Rear suspension Vertically-asymmetric Pro-Arm swing arm with Pro-Link
Rear wheel travel 120mm (4.7 in.)
Rear damper Nitrogen gas-filled damper with reserve tank
Front wheel 16x3.5 in. magnesium alloy
Rear wheel size 17x5.5 in. magnesium alloy
Front tire size 130/70-ZR16 (Michelin TX11 radial)
Front tire pressure 270 kPa (2.70 kg/cm²; 39 psi.)
Rear tire size 180/55-ZR17 (Michelin TX23 radial)
Rear tire pressure 290 kPa (2.90 kg/cm²; 42 psi.)
Front brakes Dual disc; 310mm (12.2 in.) with 4-piston caliper and semi-metallic pads
Rear brake Single ventilated disc; 220mm (8.7 in.) with dual-piston caliper and sintered metal pads
Caster angle 24-deg 30'
Trail length 88mm (3.5 in.)
Fuel tank capacity 17.0 liters (3.74 Imp gal., 4.5 U.S. gal.)
Engine: Bore (Major x Minor axis) 101.2 x 50.6mm (3.98 x 1.99 in.) (Equivalent to 75.3mm (2.96 in.) when calculated as a circle)
Stroke 42.0mm (1.65 in.)
Displacement 747.7 cm³ (45.6 cu in.)
Compression ratio 11.7 : 1
Valve train Cam gear-driven DOHC; 8 valves per cylinder
Intake valve opens (@ 1mm (0.04 in.) lift) 20-deg. BTDC
Intake valve closes (@ 1mm (0.04 in.) lift) 50-deg. ABDC
Exhaust valve opens (@ 1mm (0.04 in.) lift) 46-deg. BBDC
Exhaust valve closes (@ (0.04 in.) 1mm lift) 16-deg. ATDC
Lubrication system Forced pressure and wet sump with oil cooler
Oil pump type Trockoid
Cooling system Liquid cooled
Air filtration Oiled paper filter
Crankshaft type Unit-type; 5 main journals; [360-deg.]2
Engine weight 80.5kg (177.5 lb.)
Firing order #1 @ 270 deg.; #2 @ 90 deg.; #3 @ 270 deg.; #4
Cylinder arrangement 90-deg. V4
Cylinder numbering
Fuel system: Throttle body PGM-FI (Programmed Fuel Injection)
Throttle bore 30mm (1.2 in.) x 8
Drive train: Clutch system Multi-plate, wet
Clutch operation system Hydraulic
Transmission 6 speeds
Primary reduction 1.937 (62/32)
Final reduction (sprockets) 2.500 (40/16)
Drive chain slack 20-30mm (3/4~1-1/8 in.)
Drive chain size/links 525/108
Gear ratio, 1st 2.666 (40/15)
Gear ratio, 2nd 2.125 (34/16)
Gear ratio, 3rd 1.777 (32/18)
Gear ratio, 4th 1.545 (34/22)
Gear ratio, 5th 1.381 (29/21)
Gear ratio, 6th 1.240 (31/25)
Gearshift pattern Left foot operated return system: 1—N—2—3—4—5—6
Electrical: Ignition system Computer-controlled digital transistorized with electronic advance
Starting system Electric starter
Charging system Triple phase output alternator
Regulator/rectifier type SCR shorted/triple phase full-wave rectification
Lighting system Battery (Yuasa YTX12-BS)
Lubrication: Engine oil capacity at draining 3.6 liters (3.17 Imp. qt., 3.78 U.S. qt.)
Engine oil capacity at disassembly 4.7 liters (4.14 Imp. qt., 4.94 U.S. qt.)
Engine oil capacity at oil filter change 3.9 liters (3.44 Imp. qt., 4.10 U.S. qt.)
Recommended engine oil Use Honda 4-Stroke Oil or equivalent with the Honda UC oil at the prescribed ratio
Recommended engine oil viscosity SAE 10W-40; API Service Classification: SE, SF or SG
Recommended oil additive Honda UC Oil
Engine oil/UC oil mixing ratio 1 liter : 50cc
Oil pressure at oil pressure switch 600 kPa (6.0 kg/cm², 228 psi) @ 6,000 rpm (80 deg.C, 176 deg.F)
PGM-FI (Programmed Fuel Injection): Starter valve vacuum difference 20mmHg [(0.8inHg)]2
Base throttle valve (for synchronization) No. 3
Idle speed (except Swiss and Austrian models) 1,300 +/- 100 rpm
Idle speed (Swiss and Austrian models) 1,500 +/- 100 rpm
Throttle grip free play 2-6mm (0.08-0.24 in.)
Ta (air temperature) sensor resistance (@ 20 deg.C/68 deg.F) 1-4 kOhms
Tw (water temperature) sensor resistance (@ fan motor operating temperature) 150-400 kOhms
Cam pulse generator resistance (@ 20 deg.C/68 deg.F) 400-600 kOhms
Fuel injector resistance (@ 20 deg.C/68 deg.F) 9-14 kOhms
Bypass solenoid valve resistance (@ 20 deg.C/68 deg.F) 28-32 kOhms
Cam pulse generator peak voltage 0.7v or more
Crank pulse generator peak voltage 0.7v or more
Manifold absolute pressure @ idle 140-180 mmHg
Fuel pressure @ idle 255 kPa (2.55 kg/cm²; 36 psi)
Fuel pump flow 150 cm³ (5.26 Imp. oz.; 5.07 U.S. oz.) or more/10 seconds
Secondary air supply system (Swiss and Austrian models only)
Air suction valve vacuum pressure 380mmHg
Clutch system: Clutch lever free play 10-20mm (0.4-0.8 in.)
Recommended clutch fluid DOT 4 brake fluid
Clutch master cylinder I.D. 14.000-14.043mm (0.5512-0.5529 in.) (~9/16")
Clutch disc thickness 3.72-3.88mm (0.147-0.153 in.)
Clutch disc service limit 3.6mm (0.14 in.)
Clutch plate warpage limit 0.30mm (0.012 in.)
Cooling system: Coolant capacity (radiator & engine) 2.9 liters (2.55 Imp. qt., 3.05 U.S. qt.)
Coolant capacity (reserve tank) 0.34 liter (0.30 Imp. qt., 0.36 U.S. qt.)
Radiator cap relief pressure 110-140 kPa (1.10-1.40 kg/cm², 16-20 psi)
Thermostat begins to open 80-84 deg.C (176-183 deg.F)
Thermostat fully opens 95 deg.C (203 deg.F)
Thermostat valve lift 8.0mm (0.23 in.) min.
Front suspension: Fork spring free length 251.7mm (9.91 in.)
Fork spring direction Taper-wound coil facing up
Recommended fork oil Fork fluid [(5wt)]2
Fork oil level 56mm (2.2 in.)
Fork oil capacity 580 cm³ (20.36 Imp. oz; 19.62 U.S. oz)
Steering bearing pre-load 9-14 Nm (0.9-1.4kg; 2.0-3.1 lb.)
Rear suspension: Shock spring free length 160.0mm (6.30 in.)
Shock spring installed length 147.6mm (5.81 in.)
Nitrogen gas pressure 980 kPa (10.0 kg/cm²; 142 psi)
Brakes: Brake fluid type DOT 4
Front brake disc thickness 5.0mm (0.20 in.)
Front brake master cylinder I.D. 14.000-14.043mm (0.5512-0.5529 in.) (~9/16")
Front brake caliper cylinder I.D. (upper) 27.000-27.050mm (1.0630-1.0650 in.)
Front brake caliper cylinder I.D. (lower) 30.230-30.280mm (1.1902-1.1921 in.)
Rear brake disc thickness 9.0mm (0.35 in.)
Rear brake master cylinder I.D. 12.700-12.743mm (0.5000-0.5017 in.) (~1/2")
Rear brake caliper cylinder I.D. 25.400-25.450mm (1.0000-1.0020 in.)
Battery/Charging system: Reg/rec regulated voltage 12.6-15.0v @ 3,000rpm
Battery capacity 12v-10Ah
Battery charging rate (normal) 1.2A/5-15 hr.
Battery charging rate (quick) 5.0A/1 hr.
Battery voltage 13.1v
Front brake master cylinder I.D. 14.000mm (0.5512 in.) (9/16")
Front brake caliper cylinder I.D. (upper) 32.030mm (1.2610 in.)
Current leakage 1.5mA maximum
Alternator/charging coil resistance (@ 20 deg.C/68 deg.F) 0.1-0.5 Ohms
Ignition system: Spark plug (standard) NGK ER9EH or ND Y27FER-C
Spark plug (extended high-speed riding) NGK ER10EH or ND Y31FER-C
Spark plug (cold climate/below 5 deg.C/41 deg.F) NGK ER8EH or ND Y24FER-C
Spark plug gap 0.6-0.7mm (0.024-0.028 in.)
Ignition timing "F" mark (except Swiss and Austrian models) 15-deg. BTDC @ 1,300rpm
Ignition timing "F" mark (Swiss and Austrian models) 10-deg. BTDC @ 1,500rpm
Advance starts 2,000rpm
Advance stops 5,000rpm
Lights/Meters/Switches: Main fuse A 30A
Main fuse B 55A
Fuse 30A x 1; 10A x 6
Headlight (high beam) 12v 60/55w (H4; low beam portion not used)
Projector headlight (low beam) 12v 55w (H3)
Position light 12v 5w
Turn signal lights 12v 21w
Tail/brake light 12v 5/21w x 2
License light 12v 5w
Turn signal indicator 12v 3w x 2
High beam indicator 12v 1.7w
Neutral indicator 12v 1.7w
Side stand indicator 12v 3w
Oil pressure warning indicator 12v 3w
Fuel reserve warning indicator 12v 3w
PGM-FI warning indicator 12v 1.7w
Instrument light 12v 1.7w x 5
LCD light 12v 8w
Starting system: Starter motor brush length 12.0-13.0mm (0.47-0.51 in.)


  1. This text appears (verbatim) at the front of the Workshop Manual

  2. Unconfirmed Home Copyright © 1999-2011 [Sources: Honda NR750N Workshop Manual (pn. 67MT700), Parts Catalog (pn. 13MT7N92) and Owners Manual (pn. 32MT7600C)]