The Honda CB600F (known as the Hornet in Europe and Brazil and 599 in the U.S.) is a standard motorcycle manufactured by Honda. It is powered by a 599 cc (36.6 cu in) liquid-cooled inline-four engine, originally a detuned version of that in the Honda CBR600 sport bike, which currently produces around 102 bhp (76 kW). The 'Hornet' name was not taken to North America as AMC, and its successor, Chrysler, had trademarked the name with the AMC Hornet.

The Honda CB600F Hornet was introduced for Europe in 1998. It was based on the CB250F that was restricted to 250 cc (15 cu in) at its home-market (Japan) because of local laws (this bike was released only in Japan from 1996 or 1997 until 2015, when it was succeeded by the CB300F). The bike has a six-speed transmission. Its suspension consists of a single shock in the rear and a conventional telescopic fork in the front until it was succeeded by an upside-down fork in 2005. Its brakes are dual-disc, Nissin twin piston in the front and single-disc, Nissin single piston in the rear. It was given the 16 in (410 mm) diameter front wheel and 17 in (430 mm), 180 section rear wheel setup from the Fireblade.

As a sport-oriented motorcycle that provides an upright riding position, it is considered a standard or "naked bike".

In 2000, Honda updated the Hornet, changing the 16 in (410 mm) front wheel for a 17 in (430 mm) to help corner stability and increasing the strength of the brake pass-over system on the front, making the brakes stronger. However, Honda did not increase the size of the fuel tank. A faired version, the CB600FS, was also introduced in 2000.

In 2003, Honda gave the CB600F version a make-over, with a larger fuel tank (17 L or 3.7 imp gal or 4.5 US gal as opposed to the former 16 L or 3.5 imp gal or 4.2 US gal), and 'sharper' styling. The CB600S faired version was discontinued.

In 2005, the instrument cluster was modernised, and more importantly, it was fitted with inverted front forks, to improve road-holding and cornering stability.

Honda took the Hornet to the United States and Canadian market for the 2004 and 2006 model years. It was called the 599.

The highly revised CB600F model came out in April 2007. The engine of the new motorcycle is a detuned version of the engine available in the 2007 CBR600RR giving a maximum output power of approximately 102 bhp (76 kW).

In 2011, the model got a facelift. The headlight assembly was changed and the instrument cluster uses LCD display. This bike shared many of the same components – swingarm, fork, frame, engine – as the Honda CBR600F that was reintroduced in 2011.

In 2014, the model received a major update and got a displacement increase of 49 cc, the new model is called CB650F.

### Gearbox Output Flange Repair on Honda CB 600F

**Overview**

The gearbox output flange is a critical component that connects the transmission to the rear wheel via the chain or belt system. If the output flange is damaged or worn, it can lead to issues such as vibrations, noise, or even loss of power transfer, which can affect the performance and safety of your motorcycle.

### Theory Behind the Repair

1. **How the System Works**:
- The engine produces power, which is transferred to the gearbox (transmission).
- The gearbox reduces the engine speed and increases torque, allowing the motorcycle to accelerate smoothly.
- The output flange connects the gearbox to the final drive (chain or belt), which transmits power to the rear wheel.

2. **Why Repair is Needed**:
- If the output flange is damaged (cracked, worn splines, or excessive play), it can lead to:
- Vibration: Unbalanced power transfer can cause uneven movement.
- Noise: Metal-on-metal contact can produce grinding or clunking sounds.
- Loss of Power: If the flange cannot effectively transmit power, performance will decrease.

### Tools and Materials Needed

- **Tools**:
- Socket set (including 10mm and 12mm sockets)
- Torque wrench
- Screwdrivers (flat and Phillips)
- Pliers
- Hammer
- Rubber mallet
- Gear puller (if needed)
- Cleaning cloths
- Safety goggles and gloves

- **Materials**:
- Replacement output flange (if damaged)
- New gaskets or O-rings (if applicable)
- Thread-locking compound (optional)
- Lubricant or grease

### Step-by-Step Repair Process

1. **Preparation**:
- **Safety First**: Wear gloves and safety goggles.
- **Secure the Motorcycle**: Place the bike on a stable stand to prevent it from tipping over.

2. **Remove the Rear Wheel**:
- Loosen the axle nut using the socket set.
- Remove the rear wheel by sliding it out of the swingarm. Keep track of spacers.

3. **Access the Output Flange**:
- Locate the output flange at the end of the gearbox.
- If there is a cover, remove it using the appropriate screwdriver.

4. **Inspect the Output Flange**:
- Look for signs of wear, such as:
- Cracks on the flange surface.
- Worn splines (the parts that fit onto the shaft).
- Play or movement in the flange.

5. **Remove the Flange**:
- If the flange is bolted, use the socket set to remove the mounting bolts.
- If it is stuck, use a rubber mallet to tap it gently. If necessary, use a gear puller to extract it.

6. **Clean the Area**:
- Use a cleaning cloth to wipe down the gearbox output shaft and surrounding area.
- Inspect for any debris or old gasket material that needs to be removed.

7. **Install the New Output Flange**:
- Apply a light coat of lubricant to the splines of the new flange.
- Align the new flange on the output shaft and press it into place.
- Reinstall the bolts and tighten them using a torque wrench to the manufacturer's specifications.

8. **Reassemble the Rear Wheel**:
- Slide the rear wheel back into the swingarm.
- Reinstall spacers and tighten the axle nut securely.

9. **Test the Repair**:
- Start the motorcycle and let it idle.
- Check for any unusual noises or vibrations.
- Take a short test ride to ensure everything is functioning smoothly.

### Potential Issues

- **Incorrect Installation**: Not aligning the flange properly can lead to premature wear or failure.
- **Overtightening Bolts**: This can strip threads or damage the flange, leading to the same issues as before.
- **Neglecting Other Components**: Always inspect the chain or belt and rear wheel bearings during this repair, as they work in conjunction with the output flange.

### Conclusion

Understanding how the gearbox output flange works and the importance of its repair can help you maintain your Honda CB 600F effectively. Regular inspections and timely repairs can prevent larger issues down the line, ensuring a safer and smoother ride.
rteeqp73

Replacing the catalytic converter on a Honda CB 600F involves several steps, and understanding the theory behind the process can clarify why each step is necessary. Here’s a structured breakdown:

### Theory Behind the Catalytic Converter

**Function**: The catalytic converter is a component of the exhaust system that reduces harmful emissions by converting toxic gases (CO, NOx, and unburned hydrocarbons) into less harmful substances (CO2 and N2) through chemical reactions facilitated by catalysts (usually platinum, palladium, and rhodium).

**Failure Symptoms**: A faulty catalytic converter can lead to poor engine performance, increased emissions, and possibly trigger the check engine light due to excessive backpressure or inefficient exhaust flow.

### Steps for Replacement

1. **Preparation and Safety**:
- **Tools and Materials**: Gather necessary tools (socket set, wrenches, jack stands) and a new catalytic converter.
- **Safety Precautions**: Ensure the motorcycle is cool, work in a well-ventilated area, and wear safety equipment (gloves, goggles).

2. **Accessing the Catalytic Converter**:
- **Remove the Exhaust System**: Disconnect the exhaust pipe from the engine head. This requires loosening bolts/nuts and possibly cutting exhaust straps.
- **Support the Motorcycle**: Use a motorcycle stand to keep it stable while you work.

3. **Remove the Old Catalytic Converter**:
- **Disconnect Sensors**: If your model has O2 sensors, detach them carefully to avoid damage.
- **Unbolt the Converter**: Remove bolts or clamps securing the catalytic converter to the exhaust system.
- **Take Out the Converter**: Carefully extract the old converter from the exhaust system.

4. **Install the New Catalytic Converter**:
- **Positioning**: Place the new catalytic converter in the same orientation as the old one.
- **Secure It**: Use the original bolts or clamps to fasten the converter, ensuring a tight fit to prevent leaks.

5. **Reconnect Sensors and Exhaust**:
- **Reattach O2 Sensors**: Connect any sensors in their proper locations.
- **Reassemble Exhaust**: Reconnect the exhaust pipe to the engine head, ensuring a tight seal to prevent exhaust leaks.

6. **Final Checks**:
- **Inspect for Leaks**: Start the engine and listen for any exhaust leaks at the joints.
- **Check Engine Light**: Monitor for any warning lights on the dashboard, indicating that the installation was successful.

### How the Repair Fixes the Fault

- **Restores Emission Control**: Installing a new catalytic converter reinstates the motorcycle's ability to reduce harmful emissions, complying with environmental regulations.
- **Improves Performance**: A functioning catalytic converter alleviates backpressure in the exhaust system, enhancing engine performance and efficiency.
- **Resolves Diagnostic Issues**: If the check engine light was triggered due to a faulty converter, replacing it will likely turn off the light, indicating the issue has been resolved.

By understanding the function of the catalytic converter and the steps involved in replacing it, you gain insight into how each action contributes to restoring the motorcycle's performance and compliance with emission standards.
rteeqp73

Tools & materials
- 8, 10, 12 mm socket and ratchet (common fasteners on CB600F tank/seat)
- Phillips and flat screwdrivers (for clips, hoses)
- Long-nose pliers (clamp/hose removal)
- Side cutters or small diagonal cutters (clip removal)
- Small pick or stiff dental tool (remove O‑ring/hose if stuck)
- Torque wrench (recommended for tank/seat bolts; see manual)
- Clean rags, small container for fuel drip
- Replacement PCV/crankcase breather valve (OEM part for your CB600F year or a correct 1‑way check valve rated for engine vacuum)
- Replacement vacuum hose or small hose clamps (if original is brittle)
- Light engine oil or silicone spray (to ease hose installation)
- Safety gloves and eye protection

Safety precautions
- Work on a cool engine and in a well-ventilated area away from sparks/open flame. Gas vapors are flammable.
- Put bike on centerstand or paddock stand for stability.
- Disconnect the negative battery terminal before removing the fuel tank/electrical connectors.
- Turn fuel petcock to OFF and have a small container ready for a few drips when disconnecting fuel line.
- Keep rags under the work area to catch fuel; dispose properly.
- Avoid overtightening fasteners or clamps — follow torque spec in the service manual when available.

What the part is and how to test the old one
- The “PCV” on a motorcycle is a one‑way crankcase breather/check valve between the crankcase and intake/airbox. It should let flow from crankcase → intake only.
- To test: blow into the intake side of the valve. Air should pass one way only. Reverse direction should be blocked. If it passes both ways or is sticky, replace.

Replacement parts required
- OEM PCV / crankcase breather one‑way valve for CB600F (match year/model) or equivalent one‑way check valve sized to the hose.
- Replace any brittle vacuum hose or clamps you disturb. It’s inexpensive and prevents future leaks.

Step-by-step procedure (workshop detail)
1. Preparation
- Park bike on centerstand/paddock stand. Let engine cool.
- Disconnect negative battery terminal to avoid accidental starts or sparks.
- Turn fuel petcock OFF.

2. Remove seat(s)
- Use appropriate socket or key to remove seat mounting bolts. Lift off seat and set aside.

3. Remove/raise fuel tank
- Remove tank mount bolts (usually 8–10 mm). Use socket/ratchet.
- Before lifting, disconnect fuel feed line(s) from the tank/petcock. Put a rag under and a small container for any drips.
- Disconnect vent hoses and any electrical connectors attached to the tank (fuel level sensor if present).
- Carefully lift tank straight up and back; there are rubber mounts—wiggle gently. Support the tank with a block or have an assistant hold it. Do not let it hang by fuel lines.

How the tool is used: use the socket and ratchet to remove the tank bolts; use flat screwdriver or pliers to pull off hose clamps; use side cutters for plastic clips if required.

4. Locate the PCV valve
- With the tank lifted, locate the crankcase breather hose on top of the engine/crankcase. The one‑way valve is usually inline between the crankcase and the airbox/throttle bodies. It’s typically a small plastic check valve in a rubber hose.

5. Remove old valve
- Note orientation of valve (arrow or which side goes to crankcase vs intake). Mark or photograph to ensure correct reinstallation.
- Use long‑nose pliers or flat screwdriver to loosen clamps (spring or screw clamps) and slide them back.
- Twist the valve gently while pulling it off the hose. If the hose is seized, use the pick to get under the hose lip, or apply a little penetrating oil around the connection and work it free.
- Catch any oil residue with rags. Inspect hose for cracks/soft spots—replace if brittle.

How the tool is used: pliers remove spring clips; screwdriver loosen screw clamps; pick for prying O‑rings or stuck hose.

6. Fit the new valve
- Confirm orientation: arrow must point from crankcase to intake (direction of flow to intake).
- If using a new hose, cut to length and slide onto fittings. Lightly lubricate inside of hose with a dab of engine oil to ease installation.
- Push valve fully onto hose until seated, then re‑position clamps and tighten snugly. If using screw clamps, tighten until secure but don’t crush the hose. For spring clamps, compress and locate in groove.
- Replace any O‑rings if present.

7. Reinstall fuel tank and seat
- Lower tank back onto rubber mounts, reconnect vent hoses, fuel line, and any electrical connectors. Ensure hoses are routed without kinks.
- Reinstall tank bolts and tighten to spec (use torque wrench if available; otherwise snug to manual spec). Reconnect battery negative terminal.
- Reinstall seat(s).

8. Start and check
- Turn fuel petcock ON, start engine. Let idle and observe.
- Check for any fuel drips and ensure crankcase hose connections are sealed.
- Listen for abnormal sucking or backfiring that could indicate incorrect valve orientation or leaks.
- If idle is rough initially, it may be normal for a short time while the engine re‑learns mixture; recheck all connections.

Common pitfalls & how to avoid them
- Wrong orientation: the valve only works one way. Mark orientation and install arrow toward intake.
- Reusing brittle hose: old hoses often crack. Replace hose if >5–7 years old or if you see cracking.
- Damaging plastic valve while prying: use gentle twisting motion and a pick around the hose jaw; don’t lever directly on the valve body.
- Tightening clamps too much: over-tightening can collapse hose or crack plastic valve — tighten just until secure.
- Forgetting to close petcock or disconnect battery: results in fuel spills or sparks. Always turn petcock OFF and disconnect negative battery.
- Not testing the old valve: if you reinstall the old valve thinking it’s fine, you may not resolve PCV-related issues. Test for one‑way operation.
- Kinking fuel or vacuum hoses when reinstalling tank: route hoses free and secure them so they are not pinched.
- Incorrect replacement part: get the correct OEM valve or a rated aftermarket valve—size and vacuum flow characteristics matter.

Quick testing after install
- With engine off, blow into intake side of the valve to ensure it blocks flow in the reverse direction.
- Start bike and check idle stability and vacuum hoses for leaks.

That’s all. Replace valve with correct one‑way breather, observe orientation, replace any suspect hose/clamps, torque fasteners to spec, and test.
rteeqp73