How to Troubleshoot a Kawasaki 800 Vulcan Classic

Kawasaki finally retired the Vulcan 800 Classic in 2005 after manufacturing it for nearly a decade. This cruising motorcycle was relatively well received, though it had some style and comfort drawbacks according to professional reviewers at the bike rankings website Still, reviewers did note that the bike promised power and an enjoyable ride. To perform at its best, the Vulcan 800 required regular repairs. To aid users at this task, Kawasaki included a number of troubleshooting tips in its Vulcan 800 Classic owner's manual.

Check the level of fuel in the gas tank if the engine stalls, misfires or will not start. Refill with unleaded gasoline if the fuel tank is empty.

Examine the condition of the fuel if the gas tank has adequate levels. Gummy or watery fuel may be contaminated. Take the Vulcan 800 to a mechanic to have the fuel tank drained. Refill with fresh gasoline.

Use the choke and try to restart the engine if the weather is cold. Move on to the next step if the engine still won't start or runs improperly.

Remove the spark plugs from the Vulcan 800's two cylinders, located underneath the Vulcan's seat and front console: Carefully pull the spark plug cap from each, turning each spark plug counterclockwise with a spark plug wrench, and lift gently from each cylinder.

Inspect the electrodes of each spark plug. Clean any carbon build-up with a sandblasting device or high-flash-point solvent and a wire-bristle brush.

Replace the plugs with new NGK CR7EA or ND U22ESR-N spark plugs if the electrodes on the original appear burnt, white and brittle or cracked.

Set the spark plug gap between 0.028 and 0.032 inches. This gap measures the distance inside the hook at the end of the spark plug. To widen this gap, use a spark plug gap tool to pull the hook out gently to the desired gap. To shorten the gap, press the spark plug's hook against a firm, level surface.

Restart the engine. If it still won't run properly, take the Vulcan 800 in for repairs.

Check the engine stop switch located on the left handlebar if the starter motor won't work and the engine won't turn over. If it is in the "OFF" position, switch it to "ON" for regular operation.

Check to ensure the clutch lever is pulled in and that the transmission is shifted to neutral.

Check the main fuse, located underneath the Vulcan 800's seat near the rear tire. If the connection in the centre of the fuse looks burnt or broken, replace it with a 30A fuse.

Check the battery, located under the Vulcan 800's seat. Unscrew the battery bracket bolts with a wrench, and remove the battery bracket. Remove the battery leads, first disconnecting the lead from the negative terminal and then the positive one. Carefully lift the battery out of its case.

Clean any corrosion from the battery terminals using a wire-bristle brush. Clean any debris using a solution of 1 tbsp of baking soda mixed with 1 cup of water.

Charge the battery to 12 volts before reinstallation using a separately powered charger.

Reinstall the battery, connecting the lead to the positive terminal first and the lead to the negative cable second. Put a light coat of grease on top of the battery terminal to prevent corrosion, and reinstall the bracket and seat.

Operate the electric starter. Take the Vulcan 800 in for repairs if the engine still turns over slowly.

Do not idle or operate at extremely low speeds for extended periods of time, as this can cause the engine to overheat.

Check the engine oil levels by removing the cap and dipstick from the oil filler, located on the bottom left side of the Vulcan 800. Dry the dipstick with a shop rag, return it to the oil filler and remove it once more. Engine oil levels should be between the "H" and "L" marks on the dipstick. If not, refill with SAE 10W-40 engine oil.

Check coolant levels in the reserve tank by situating the Vulcan 800 on a level surface and observing the visible level in the tank's transparent hose. Levels should be between the two marks on the side of the hose. Refill with a solution of distilled water and antifreeze if coolant levels are beneath the lowest mark.

Restart the engine and take the Vulcan 800 in for inspection if it continues to overheat.


If troubleshooting fails, Kawasaki recommends that owners take the Vulcan 800 Classic to a trained and certified dealer for major repairs.


Because gasoline and batteries release explosive fumes, do not smoke or work near an open flame when troubleshooting these systems. To prevent burns from battery acid, wear goggles and gloves when handling the Vulcan's battery.

Things You'll Need

  • Gasoline (unleaded)
  • Spark plug wrench
  • Sandblaster
  • Wire-bristle brush and high flashpoint solvent
  • NGK CR7EA or ND U22ESR-N spark plugs
  • Spark plug gap tool
  • 30A fuse
  • SAE 10W-40 engine oil
  • 1 tbsp baking soda with 1 cup of water solution
  • Separately powered 12-volt battery charger
  • Coolant
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About the Author

Brianna has been writing professionally since 2009. She has a Bachelor of Fine Arts degree and is excited to be part of a community that contributes to the free sharing of information and ideas.