The Reality of Owning a 1970s Honda CB750: What Nobody Tells You Before You Buy

When Soichiro Honda and his engineering team unveiled the CB750 Four at the 1968 Tokyo Motor Show, it fundamentally shattered the motorcycle landscape. It brought an inline four-cylinder engine, front hydraulic disc brake, electric starter, and unmatched reliability to a marketplace previously accustomed to vibrating British twins and leaking crankcases.

Today, half a century later, owning a single-overhead-cam (SOHC) CB750 (produced from 1969 to 1978) remains one of the most romanticized entry points into classic motorcycling.

However, after five years and over 22,000 miles on my 1974 CB750 K4, I can tell you that the glossy magazine retrospectives omit the gritty daily realities. Here is the unvarnished truth about living with Honda's original superbike.

---

1. The Carburetor Bank: Synchronization Is a Lifestyle

The heart of the CB750 is its bank of four Keihin round-slide carburetors. When they are clean and synchronized, the motorcycle pulls with a velvety, turbine-like crescendo that will give you goosebumps.

When they are even slightly out of tune:

• You will battle frustrating cold-start hesitation.
• Cylinder #2 and #3 will run hotter than the outer cylinders.
• Fuel economy drops off a cliff, and throttle response feels muddy below 3,500 RPM.

Mechanic’s Rule: Never adjust your carburetors until you have verified valve clearances, set point gaps, and checked static ignition timing. Ninety percent of "carb problems" are actually ignition issues in disguise.

Synchronizing a four-carb bank requires a vacuum manometer (or four matched vacuum gauges) and deliberate patience. Budget a Saturday afternoon every spring to balance throttle pull cables and idle drop screws.

---

2. Dry Sump Lubrication Nuances

Unlike modern wet-sump bikes where oil pools in the bottom of the engine pan, the SOHC CB750 employs a dry-sump oiling system with an external side-mounted oil tank under the right side cover.

Here is the trap that catches new owners: wet-sumping. If the bike sits idle for more than three weeks, oil can slowly seep past the oil pump check valve down into the crankcase. If you pull the dipstick before starting the engine, the oil level will appear empty!

WARNING: DO NOT immediately add oil if the dipstick reads low after storage!
1. Start the engine and let it idle for 3 to 5 minutes.
2. The scavenge pump will return the oil to the external tank.
3. Shut off the engine, rest on center stand, and THEN check the dipstick.

If you overfill without warming the engine, oil will vomit through the airbox breathers the moment you hit highway speeds.

---

3. Weight and Braking Realities

In modern terms, the CB750 is a heavy brute. Wet weight sits right around 520 lbs (236 kg) with a full 4.5-gallon fuel tank.

• The Front Disc: While historic for being the first mass-production front disc brake, it is a single-piston sliding caliper clamping down on an un-vented, solid stainless steel rotor. In dry weather, squeeze pressure must be deliberate and firm. In wet rain, expect a terrifying 1.5-second delay while the pads wipe water off the steel disc before friction engages.
• The Frame Geometry: The mild-steel cradle frame flexes when pushed hard through bumpy sweepers. Installing fresh bronze swingarm bushings and modern progressive fork springs is the single best handling upgrade you can make.

---

4. The Irreplaceable Reward

Why endure the quirks? Because once you get rolling on a two-lane country blacktop, the CB750 delivers pure mechanical theater.

There are no ride-by-wire lag, no traction control interventions, and no digital LCD distractions. The sound of four exhaust pipes harmonizing into a 7,000 RPM wail is an experience no modern retro-tribute bike can duplicate. If you are willing to learn basic wrenching, the CB750 will reward you with a lifetime of reliable, authentic freedom.