|
|
| Line 58: |
Line 58: |
| [[File:Honda-CB750K4-74.jpg|600px|Honda CB750K4]] | | [[File:Honda-CB750K4-74.jpg|600px|Honda CB750K4]] |
| [[File:honda-cb750k4-74-01.jpg|600px|Honda CB750K4]] | | [[File:honda-cb750k4-74-01.jpg|600px|Honda CB750K4]] |
|
| |
| == Overview ==
| |
|
| |
| Honda CB 750 Four K4
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
|
| |
| The CB750K4 Four was sold in 1974 and was available
| |
| in one of three colors: Flake Sunrise Orange, Freedom Green Metallic, or Boss
| |
| Maroon Metallic. The gas tank stripes were white, gold and black. The side
| |
| covers were smaller than the K0 model and there were no slots on the leading
| |
| edge. The speedometer showed increments of 20 (i.e., 20, 40, 60, 80, etc.). The
| |
| upper forks were chrome. The white tank pinstripe was wider than the K3 model.
| |
| The headlight shell was black. The taillight and side reflectors were larger
| |
| than the K1 model. There was a two-throttle cable system (pull open and pull
| |
| closed). The exhaust system was a 4-into-4. The engine was a 736cc SOHC 2-valve
| |
| dry sump inline 4 cylinder linked to a 5-speed transmission and chain drive. The
| |
| serial number began CB750-2300001.
| |
|
| |
|
| |
|
| |
| It is no exaggeration to say the Honda CB750
| |
| is the most significant motorcycle ever made and altered the
| |
| world of motorcycling forever. Prior to the CB750 you had two
| |
| choices in motorcycles: You could have a small, reliable
| |
| Japanese bike or you could have a larger, faster but unreliable
| |
| bike. The CB750 proved to the doubters that the Japanese could
| |
| build a large bike (a 750 was considered monster-size in those
| |
| days.) It was the first to come standard with a hydraulic disk
| |
| brake. It had both electric and kick start. It started every
| |
| time, parts didn't fall off and it didn't leak oil. We take
| |
| these things for granted today but it really meant something in
| |
| 1970!
| |
|
| |
| It wasn't all about practical everyday driving either. The CB750
| |
| was equally at home on the racetrack. A modified CB750 won the
| |
| 1970 Daytona and set a new track record. The world took notice.
| |
|
| |
| The British motorcycle industry, notorious for unreliable
| |
| motorcycles and already on the ropes, was finally put out of
| |
| their misery. This bike and its successors very nearly put
| |
| Harley-Davidson out of business too. The CB750 raised the bar in
| |
| the industry. You had to either improve your designs or get out
| |
| of the motorcycle business.
| |
|
| |
| Honda built about a million of the CB750s over its ten year
| |
| history. To get a feel for how popular that is consider that
| |
| BMW, which has been making motorcycles far longer than Honda,
| |
| only recently rolled its millionth bike off the assembly line.
| |
|
| |
| I was only five years old when the CB750 first appeared so I was
| |
| too young to understand its importance. The CB750 was a common
| |
| "college" bike when I was in school. They were reliable,
| |
| plentiful and cheap. You could keep those bikes going forever. I
| |
| bought this bike to relive those times and see if a twenty-seven
| |
| year old bike could still compare to a modern machine.
| |
|
| |
| My 1974 CB750 came from a collector who had partially restored
| |
| it. It is in excellent mechanical condition, very good cosmetic
| |
| condition and the mileage is low (13,000 miles when purchased.)
| |
| It's a good candidate to compare to modern motorcycles. My
| |
| girlfriend has named her "Pumpkin" for her bright orange color.
| |
|
| |
| On to the good stuff. How is it to ride? The short answer is it
| |
| is still fun to ride today. No, Pumpkin can't match modern
| |
| motorcycles in many ways but the differences are not annoying
| |
| and there is a certain special satisfaction when riding a bike
| |
| that is a part of history.
| |
|
| |
| The differences become pronounced once you start to push the
| |
| bike and feel around the edges. The CB750 is much heavier than
| |
| modern bikes and perhaps more important it carries its weight
| |
| high. You have to keep this in mind when corning at speed but it
| |
| generally doesn't get in the way. The single disk brake with its
| |
| one piston caliper was the marvel of its day but pales in
| |
| insignificance compared to something like the antilock power
| |
| brakes on my BMW R1150RT. The right attitude for any bike of
| |
| this vintage is to think of the brakes as something that slow
| |
| you down rather than stop you.
| |
|
| |
| Acceleration is quick and torque is adequate at high revs as you
| |
| would expect in an inline four. She can keep up with modern
| |
| sport bikes in the straights although the handling is inferior
| |
| in the curves.
| |
|
| |
| The engine takes a few minutes to warm up before it's happy.
| |
| This is still true today with modern inline fours but computer
| |
| controlled ignition and fuel injection take all the fun out of
| |
| it. You have to adjust the idle level and there never really is
| |
| anything like keeping it spot on. After riding at high speed for
| |
| several minutes the engine reaches its maximum normal operating
| |
| temperature and you will notice the idle creeping up to 2,000
| |
| rpm. Just live with it or get used to reaching behind the carbs
| |
| and adjusting the idle screw with your left hand. Careful not to
| |
| burn yourself!
| |
|
| |
| The petcock is oddly on the right side of the frame. What
| |
| happens when you're riding and have to switch to reserve? The
| |
| only safe thing to do is pull over to turn the petcock.
| |
|
| |
| But these are nothing more than little quirks that give the bike
| |
| its character. Pumpkin is still every bit as competent a street
| |
| bike as she was in 1974 and none of the pleasure has faded.
| |
|
| |
| There is a reassuring feeling about having the kickstart on the
| |
| bike. Honda felt that customers weren't ready to trust an
| |
| electric starter so they included one. Pumpkin starts on the
| |
| first or second kick when warm. I haven't tried to kickstart her
| |
| when cold.
| |
|
| |
| I'm glad to have her. Despite her age she still puts a smile on
| |
| my face and that is, after all, the final test.
| |
|
| |
|
| |
|
| |
|
| |
| {| class="wikitable"
| |
| |-
| |
| !Make Model
| |
| |Honda CB 750 Four K4
| |
| |-
| |
| !Year
| |
| |1974
| |
| |-
| |
| !Engine Type
| |
| |Four stroke, transverse four cylinder, SOHC, 2 valve per cylinder.
| |
| |-
| |
| !Displacement
| |
| |736 cc / 44.9 cub in.
| |
| |-
| |
| !Bore X Stroke
| |
| |61 х 63 mm
| |
| |-
| |
| !Compression
| |
| |9.0:1
| |
| |-
| |
| !Cooling System
| |
| |Air cooled
| |
| |-
| |
| !Lubrication
| |
| |Dry sump
| |
| |-
| |
| !Induction
| |
| |4 x 28 mm Keihin carburetors
| |
| |-
| |
| !Ignition
| |
| |Battery, ignition coil
| |
| |-
| |
| !Spark Plug
| |
| |NGK D8ES-L, NDX 24 ES
| |
| |-
| |
| !Starting
| |
| |Electric, kick
| |
| |-
| |
| !Max Power
| |
| |50 kW / 67 hp @ 8000 rpm
| |
| |-
| |
| !Max Torque
| |
| |44 lb-ft / 60 Nm @ 7000 rpm
| |
| |-
| |
| !Clutch
| |
| |Multi-plate, wet
| |
| |-
| |
| !Transmission
| |
| |5 Speed
| |
| |-
| |
| !Final Drive
| |
| |Chain
| |
| |-
| |
| !Gear Ratios
| |
| |1st 13.99 / 2nd 9.54 / 3rd 7.45 / 4th 6.14 / 5th 5.26:1
| |
| |-
| |
| !Frame
| |
| |Tubular steel duplex cradle
| |
| |-
| |
| !Front Suspension
| |
| |Telescopic forks non adjustable.
| |
| |-
| |
| !Front Wheel Travel
| |
| |143 mm / 5.6 in.
| |
| |-
| |
| !Rear Suspension
| |
| |Swingarm, dual shocks, preload adjustable.
| |
| |-
| |
| !Rear Wheel Travel
| |
| |85 mm / 3.3 in.
| |
| |-
| |
| !Front Brake
| |
| |Single 296 mm disc
| |
| |-
| |
| !Rear Brake
| |
| |179 mm Drum
| |
| |-
| |
| !Front Tire
| |
| |3.25-19
| |
| |-
| |
| !Rear Tire
| |
| |4.00-18
| |
| |-
| |
| !Rake
| |
| |27°
| |
| |-
| |
| !Trail
| |
| |95 mm / 3.7 in
| |
| |-
| |
| !Dimensions
| |
| |Length: 2175 mm / 85.6 in. Width: 870 mm / 34.3 in. Height: 1170 mm / 46.1 in.
| |
| |-
| |
| !Wheelbase
| |
| |1453 mm / 57.2 in.
| |
| |-
| |
| !Seat Height
| |
| |810 mm / 31.9 in.
| |
| |-
| |
| !Ground Clearance
| |
| |140 mm / 5.5 in.
| |
| |-
| |
| !Wet Weight
| |
| |218 kg / 479 lbs
| |
| |-
| |
| !Fuel Capacity
| |
| |17 L / 4.5 US gal
| |
| |-
| |
| !Reserve
| |
| |5 L / 1.3 US gal
| |
| |-
| |
| !Oil Capacity
| |
| |3.5 L / 3.7 US quarts
| |
| |-
| |
| !Consumption Average
| |
| |6.9 L/100 km / 14.6 km/l / 34.3 US mpg
| |
| |-
| |
| !Braking Distance 48 Km/h / 30 Mph - 0
| |
| |10 m / 32.9 ft
| |
| |-
| |
| !Braking Distance 97 Km/h / 60 Mph - 0
| |
| |41 m / 135.7 ft
| |
| |-
| |
| !Standing ¼ Mile
| |
| |13.5 sec / 100.9 mph
| |
| |-
| |
| !Top Speed
| |
| |198 km/h / 123.2 mph
| |
| |-
| |
| !Colours
| |
| |Flake sunrise orange, Freedom green metallic, or Boss maroon metallic
| |
|
| |
| |}
| |
|
| |
| [[Category:Honda motorcycles]]
| |
