2012 Suzuki RM85 Smokes on Startup: Causes & Fixes

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Understanding Startup Smoke on the 2012 Suzuki RM85

Seeing smoke from your 2012 Suzuki RM85 when you first fire it up can be concerning, but it isn't always a sign of trouble. Knowing when smoke is normal and when it signals a problem helps you keep your RM85 running strong and reliable.

When Is Startup Smoke Normal?

  • Cold Starts: A brief puff of smoke is common when starting the RM85 after it's been sitting. This is often due to condensation or a small amount of oil that has settled in the exhaust or combustion chamber.
  • Premix Oil: The RM85 uses a premix of oil and fuel. Some smoke at startup is expected as the oil burns off, especially if the bike hasn't run in a while.

As long as the smoke is light, dissipates quickly, and doesn't persist as the engine warms up, it's usually nothing to worry about.

When Smoke Indicates a Problem

If your 2012 Suzuki RM85 produces thick, continuous smoke or the smoke is unusually blue or white, it may be time to investigate further. Persistent smoke can point to issues that need attention to prevent engine damage or poor performance.

Common Causes of Excessive Startup Smoke

  • Incorrect Premix Ratio: Using too much oil in your fuel mix is a leading cause of heavy smoke. The RM85 requires a specific oil-to-fuel ratio. Too much oil leads to excessive burning and visible smoke.
  • Oil Pooling in the Crankcase or Exhaust: If the bike has been stored for a while, oil can settle in the crankcase or exhaust. On startup, this oil burns off, causing a smoky exhaust. This should clear up after a short ride.
  • Worn Crank Seals: Damaged or worn crank seals can allow transmission oil to seep into the combustion chamber, resulting in persistent blue or white smoke. This is more than just a startup issue and usually continues as the engine runs.
  • Rich Fuel Mixture: A carburetor that is set too rich can cause incomplete combustion, leading to more smoke. This is often accompanied by fouled spark plugs and sluggish performance.

Diagnosing the Source of Smoke

To pinpoint the cause of smoke on your 2012 Suzuki RM85, consider the following steps:

  • Check the Premix Ratio: Confirm you're using the correct oil-to-fuel ratio. Too much oil is a common culprit for excessive smoke.
  • Observe the Smoke: Note the color and duration. Brief, light smoke is normal. Thick, blue, or white smoke that lingers suggests oil burning or seal issues.
  • Inspect for Oil Leaks: Look for oil residue around the crankcase, exhaust, and spark plug. Leaks can indicate seal problems.
  • Monitor Performance: If the bike runs rough, fouls plugs, or loses power along with smoking, a mechanical issue is likely.

Practical Fixes for Startup Smoke

  • Adjust the Premix: Drain the fuel tank and refill with the correct oil-to-fuel ratio. This simple step often resolves excessive smoke.
  • Run the Bike: If the RM85 has been sitting, take it for a short ride. This burns off pooled oil in the exhaust and crankcase.
  • Clean the Carburetor: If you suspect a rich mixture, clean and adjust the carburetor to ensure proper fuel delivery.
  • Replace Crank Seals: If smoke persists and you notice oil loss or contamination, replacing the crank seals may be necessary. This is a more involved repair but essential for long-term engine health.
  • Inspect Spark Plug: Remove and check the spark plug. Excessive oil fouling can indicate over-oiling or seal issues.

Preventing Future Smoke Issues

  • Always use the recommended oil-to-fuel ratio for your 2012 Suzuki RM85.
  • Store the bike with the fuel petcock off and run the carburetor dry before long-term storage to prevent oil pooling.
  • Perform regular maintenance, including checking seals and cleaning the carburetor.
  • Warm up the engine properly before riding to allow any residual oil to burn off gradually.

Summary

Startup smoke on the 2012 Suzuki RM85 is often normal, especially after sitting or with a fresh premix. However, persistent or heavy smoke can signal issues like incorrect premix ratios, oil pooling, or worn crank seals. By understanding the causes and following practical fixes, you can keep your RM85 running clean and strong. Regular maintenance and attention to detail will help you enjoy more trouble-free rides on your Suzuki.

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Disclaimer: This guide is provided for general informational purposes only and is not intended to replace your motorcycle's official owner's manual. Always refer to your manufacturer's documentation for model-specific instructions, torque specifications, safety procedures, and maintenance requirements. If you are unsure or inexperienced, consider seeking assistance from a qualified mechanic or technician.