Why is my Honda Rebel motorcycle blowing white smoke?

Can someone tell me why my 2005 Honda Rebel motorbike is blowing white smoke like crazy, especially when I shift gears or the engine heats up. I’ve tried some basic stuff, but nothing’s working.

Response

I had a similar nightmare with my Rebel. Turned out to be the valve stem seals. A bit of a fixer-upper, replacing those seals, and voila – problem solved.

Solutions that Worked for Users

Solution	Users Who Found Success	Approx. Cost (USD)	Approx. Time Needed (Minutes)
Valve Stem Seal Replacement	2	$50 (for parts)	120
Thorough Carburetor Cleaning	1	$20 (for cleaning supplies)	60
Compression and Leakdown Tests	1	$0 (if self-performed)	30

Symptoms

• White smoke from the exhaust, particularly noticeable when shifting or engine is hot
• Possible oil smell in the smoke

Possible Causes

• Valve stem seals failing, allowing oil into the combustion chamber
• Carburetor issues, leading to improper fuel mixture
• Compression problems due to worn rings or valve issues

Solutions that Worked

1. Valve Stem Seal Replacement

• What I Did: Replaced the worn valve stem seals to prevent oil from leaking into the combustion chamber.
• Outcome: The white smoke issue was resolved, and the bike ran smoothly.
• Personal Experience: After replacing the seals, my Rebel’s exhaust cleared up significantly.
• Estimated Cost: $50 (for parts)
• Time Needed: 120 minutes
• Detailed Steps:
  1. Prepare Your Workspace: Ensure you have a clean, well-lit area to work in. Gather all necessary tools, including a valve spring compressor, new valve stem seals, and basic hand tools.
  2. Remove the Cylinder Head Cover: Carefully remove the cylinder head cover to access the valves. This might require removing other components depending on your bike model.
  3. Compress the Valve Springs: Use the valve spring compressor to carefully compress and remove the valve springs, exposing the valve stem seals.
  4. Replace the Valve Stem Seals: Remove the old seals and replace them with new ones. Be gentle to avoid any damage to the valve stems.
  5. Reassemble: Put back the valve springs and the cylinder head cover. Ensure all components are securely fastened.
  6. Test Your Work: Start the engine and let it idle to check for any immediate issues.
• Handy Tips:
  • Keep track of all parts and their placement during disassembly.
  • Consider replacing other wear parts like the valve cover gasket.
• Expert Tip: Regularly check for signs of oil leakage around the valve cover, as it can be an early indicator of valve stem seal issues.

2. Thorough Carburetor Cleaning

• What I Did: Disassembled and thoroughly cleaned the carburetor, including jets and passages.
• Outcome: Improved fuel mixture and elimination of white smoke.
• Personal Experience: Cleaning the carburetor restored the engine’s performance.
• Estimated Cost: $20 (for cleaning supplies)
• Time Needed: 60 minutes
• Detailed Steps:
  1. Remove the Carburetor: Carefully detach the carburetor from the engine. Make sure to disconnect the fuel lines and throttle linkage.
  2. Disassemble the Carburetor: Take apart the carburetor, paying close attention to the arrangement of components.
  3. Clean Each Part: Soak metal parts in a carburetor cleaning solution. Use a brush and compressed air to clean all passages and jets.
  4. Reassemble and Reinstall: Put the carburetor back together and reinstall it on the bike. Ensure all connections are secure.
  5. Adjust Settings: Adjust the idle and mixture settings as per the manufacturer’s specifications.
• Handy Tips:
  • Take photos during disassembly for reference during reassembly.
  • Replace any worn or damaged parts like gaskets or o-rings.
• Expert Tip: Regular carburetor maintenance can prevent many common issues, including white smoke from the exhaust.

3. Compression and Leakdown Tests

• What I Did: Performed a compression test and a leakdown test to check for engine health.
• Outcome: Identified and addressed issues with engine compression.
• Personal Experience: These tests helped diagnose the underlying cause of the smoke.
• Estimated Cost: $0 (if self-performed)
• Time Needed: 30 minutes
• Detailed Steps:
  1. Warm Up the Engine: Ensure the engine is at operating temperature for accurate results.
  2. Perform the Compression Test: Use a compression tester on each cylinder, noting the readings.
  3. Conduct the Leakdown Test: Pressurize each cylinder and listen for air escaping to identify leaks.
  4. Analyze Results: Compare the results to the manufacturer’s specifications to identify any issues.
• Handy Tips:
  • Perform these tests regularly as part of routine maintenance.
  • Investigate any discrepancies in compression between cylinders.
• Expert Tip: Regular engine checks, including compression tests, are vital for early detection of potential issues.

Motorcycle Models Where This Worked

• 2005 Honda Rebel
• 2004 Honda Rebel 250
• 1999 Honda Rebel