Honda CBR400RR NC29 - Common Issues & Solutions.

[yorzeal92]

Hi all,
Been seeing a lot of questions popping up lately about the NC29, so thought I'd start a thread compiling common issues and their possible solutions. Hopefully, this will save some folks time and headaches!
Here's what I've come across so far, please feel free to add your own experiences and solutions!
**1. Starting Issues (Especially when cold):**
* **Possible Cause:** Weak battery. The NC29's charging system isn't the strongest, so a slightly weak battery can struggle to turn the engine over, especially in colder weather.
* **Solutions:**
* Check battery voltage (should be above 12.5V when resting).
* Consider a new battery.
* Ensure good connections at the battery terminals and starter motor.
* Check the charging voltage when the engine is running (should be around 13.5-14.5V).
* **Possible Cause:** Dirty Carburettors.
* **Solutions:**
* Clean Carbs
* Replace Jets
**2. Overheating:**
* **Possible Cause:** Low coolant level or air in the system.
* **Solutions:**
* Check coolant level and top up if necessary.
* Bleed the cooling system to remove any air pockets.
* Inspect hoses for leaks.
* **Possible Cause:** Faulty thermostat.
* **Solutions:**
* Test the thermostat in hot water to ensure it opens properly.
* Replace the thermostat if it's not working correctly.
* **Possible Cause:** Clogged radiator.
* **Solutions:**
* Flush the radiator.
**3. Rough Running/Misfiring:**
* **Possible Cause:** Spark plug issues.
* **Solutions:**
* Check spark plugs for wear or fouling.
* Replace spark plugs with the correct type and gap.
* **Possible Cause:** Carburettor issues (again!).
* **Solutions:**
* Ensure carburettors are properly balanced.
* Clean and inspect jets and needles.
* Check for air leaks around the carburettor manifolds.
**4. Weak Front Brakes:**
* **Possible Cause:** Air in the brake lines or worn brake pads.
* **Solutions:**
* Bleed the brake system.
* Replace brake pads.
* Check brake discs for wear.
**5. Cam Chain Tensioner (CCT):**
* **Issue:** The original CCT is known to be weak and can cause rattling noises.
* **Solutions:**
* Replace with a manual CCT (requires careful adjustment).
* Replace with an updated automatic CCT (various aftermarket options available).
**Disclaimer:** I am not a qualified mechanic, this is just a compilation of information I have found, use this information at your own risk.
Please add your own experiences and solutions, let's make this a useful resource for all NC29 owners!
Cheers!.