CB750 K0: 1969 – 1970
|Production Dates||1969-1970 Black Widow 5-1970 production date. Rebuild dates 11-2019 – 4-2020 proposed|
|Production Numbers||53,400 (sand-cast 7,400)|
|Starting Frame#||1000001 Black Widow 10368XX|
|Starting Engine#||E1000001 Black Widow E10366XX|
|Colors||Candy Blue Green for for this build.|
|Features||Tank, side covers, fork uppers and headlight shell were painted the same color. The throttle linkage used separate cables to each carb. All carbs fully rebuilt.|
New wheel bearing front and rear along with seals. Also new Honda DID rims and tires Dunlop K87 rear Dunlop F11 front. Real axle and axle nut re-chromed.
Rechromed original K0 front fender, new speedometer cable and new front caliper along with new front brake pads.
The original front caliper arm was disassembled service with new seals and reattached.
All new exterior engine seals all side covers and valve cover were polished, and the oil pump rebuilt with new seals o-rings.
New, main wiring harness new points harness, new oil temp harness new headlight harness new safety switch harness, new dynamo harness and connector.
New rear shocks and rebuild front forks with new fork tube and new Honda fork seals, fork oil used Honda. New compression washers in front fork drain and lower leg attachment.
New low profile crash bars.
New front caliper, new brake lines with new compression washers, new front brake pads and rear brake shoes.
Triple tree rebuilt with new tapered roller bearings and seals not ball bearings.
New handlebar switches.
Rechromed original kick start arm and rechromed original starter motor cover.
New points cover from Honda.
New points, and condensers along with new NGK D-8ES spark plugs.
New clutch cable Honda.
Rechromed original clutch plate cover.
Rechromed original brake arm.
New HM300 exhaust with baffles Honda.
New center stand spring and kick stand spring both Honda.
New foot peg rubbers front and rear Honda.
New fuel lines, new drain and vacuum lines.
Rechromed original K0 rear fender
|Overall length||85.0 in.||2,160 mm|
|Overall width||34.8 in.||885 mm|
|Overall height||45.5 in.||1,155 mm|
|Wheel base||57.3 in||1,455 mm|
|Seat height||31.5 in.||800 mm|
|Foot Peg Height||12.2 in.||310 mm|
|Ground Clearance||5.5 in.||160 mm|
|Curb weight||517.3 lb||235 kg|
|Weight distribution L/R||271.1/209.5 lb||123/205 kg|
|Frame & Suspension|
|Type||Double cradle tubular steel|
|Front Suspension||Telescopic fork, travel 5.6 in., 143mm|
|Rear Suspension||Swing arm, travel 3.3 in., 85mm|
|Front Tire Size, Type||3.25-19 (4PR) Rib tire, tire air pressure 2.0 kg/cm2, 28 psi 111577 Dunlop F11|
|Rear Tire Size, Type||4.00-18 (4 PR) Block tire, tire air pressure 2.0 kg/cm2, 28 psi) 122371 Dunlop K87|
|Front Brake||Disk brake, lining area 2.9in2x2, 19cm2x2|
|Rear Brake||Internal expanding shoe, lining area 8.2in2x2, 53cm2x2|
|Fuel Capacity||4.7 US gal, 3.9 Imp. gal||18 liter|
|Fuel Reserve Capacity||1.3 US gal, 1.1 Imp. gal||5 liter|
|Trail Length||3.74 in.||95mm|
|Front Fork oil capacity||7.0-7.3 oz||220-230 cc|
|Type||Air-cooled, 4-stroke, O.H.C. engine|
|Cylinder Arrangement||4-cylinder in line|
|Bore and Stroke||2.401×2.408 in.||61×63 mm|
|Displacement||44.93 cu in||736 cc|
|Maximum Horsepower||67 BHP@8,000 rpm|
|Maximum Torque||44.12 lb-ft@7,000 rpm||6.1 kg-m@7,000 rpm|
|Carburetor, Venturi Dia.||4x28mm Keihin, slide type|
|Valve train||Chain driven overhead camshaft|
|Oil Capacity||7.39 US pt, 6.16 Imp. pt||3.5 liter|
|Oil Tank Capacity||4.22 US pt., 3.55 Imp. pt||2 liter|
|Lubrication System||Forced pressure and dry sump|
|Air filtration||Paper element|
|Valve Tappet Clearance||Intake: 0.002in./0.05mm||Exhaust: 0.003in./0.08mm|
|Engine weight (Wet)||176.3 lb||80 kg|
|Air screw opening||1 1/8 turn|
|Idle speed||900 rpm|
|Carb main bore||1.102in.||28mm|
|Transmission||5-speed, constant mesh|
|Gear Ratio I||2.500:1|
|Gear Ratio II||1.708:1|
|Gear Ratio III||1.333:1|
|Gear Ratio IV||1.097:1|
|Gear Ratio V||0.939:1|
|Final Reduction||2.667:1 (17T x 46T)|
|Type||12v, negative earth|
|Ignition||Coil and contact breaker, spare spark|
|Starting system||Electrical motor and kick start|
|Alternator||3-phase 12 V 0.21kW@5,000 rpm|
|Battery Capacity||12V – 14 amp hour|
|Spark plug||NGK D-8ES|
|Spark plug gap||0.024 ~ 0.028 in.||0.6 ~ 0.7 mm|
|Points gap||0.012 ~ 0.016 in.||0.3 ~ 0.4 mm|
|I’ve been bitten by a Black Widow Spider during this build. I have also dislocated my left shoulder working on this project it’s better now. I’ve also suffered numerous cuts and scrapes during this build more than normal. After picking this ratted out CB750 K0 outside of Reno my car eat its power steering pump in Missouri. I’ve been forced to wait all day to sign for international packages on many occasions during this build. Tire’s from Japan, gauges from Europe, parts from Canada, and lot’s of parts from Japan. This is one of the last barn finds to be fully restored.|