How to Tune Up a 1986 Honda FourTrax

The Honda FourTrax is a series of all-terrain vehicles released to consumers originally for the 1986 model year. Similar models date back 1984, but the FourTrax 4x4 name was first used in this year. A 350 cc motor first adorned the FourTrax models, featuring a four-stroke, single-cylinder design. By 1988, this ATV not only became the world's best selling all-terrain vehicle, but it also paved the way for which modern ATVs would be designed and manufactured. With the right precision care and tuning, the classic 1986 Honda FourTrax can be preserved in both performance and reliability.

Things You'll Need

  • 15w50 motor oil
  • Oil filter
  • Oil recycle container
  • Spark plugs
  • Spark plug wires
  • Engine battery
  • Wrench set
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Instructions

  1. Oil and Oil Filter

    • 1

      Park the Honda FourTrax in a secured location where oil can be drained and replaced. The oil and filter should be replaced periodically, largely due to the amount and harshness the ATV is driven.

    • 2

      Place a recycle container underneath oil pan to catch used oil. Oil should never be disposed of by means of a regular trash can or any type of sewage drain. Take the old oil into your local dealer if there is any confusion.

    • 3

      Drain the old oil by removing the plug at the bottom of the oil pan. Wait for all oil to empty before replacing plug back into oil pan.

    • 4

      Use the necessary wrench to unscrew the old oil filter from its position. Turn counterclockwise to remove.

    • 5

      Replace the old filter with a new oil filter. Fill new filter ¾ full with new oil to ensure no runoff occurs when tightening filter. The filter should be hand-screwed into place.

    • 6

      Fill the engine partially with new oil by using a funnel to administer. Check the dipstick to monitor oil levels, adding oil as often as needed to reach adequate levels.

    Spark Plugs

    • 7

      Unhook the negative connection from the battery supply of the FourTrax. A safe environment for engine part replacement like spark plugs is necessary.

    • 8

      Remove any spark plug wires that appear to be frayed, tarnished, dirty, or any other type of condition other than good. Use the necessary wrench size to remove. The electrical current flow in an ATV's ignition system is vital to maintaining consistent operation once the motor has been started.

    • 9

      Spot any spark plugs that seem dirty, blown, wet, overheated or damaged and removed. Spark plugs are cheap replacements, so substitution is more efficient than any attempt to clean or repair.

    • 10

      Attach new wires to locations where old ones were removed.

    • 11

      Insert new spark plugs into gaps where old ones were removed. Plugs can be installed by hand instead of using a tool.

    • 12

      Reattach spark plug wires to their corresponding plugs to complete this process.

    Engine Battery

    • 13

      Remove the FourTrax seat and disconnect the battery of the engine by removing the positive and negative connection. This should still be unhooked from its connection from the previous action, but both connections need to be taken off at this point.

    • 14

      Loosen the battery ties by using the necessary wrench to remove the bolts. Set the bolts aside in a safe location, because they will be needed for the new battery.

    • 15

      Remove the old battery carefully from its former location. Make sure that the battery is disposed of properly, for it contains hazardous material. Consult your local dealer if there is any confusion.

    • 16

      Lower the new battery into place and make sure it is secured properly.

    • 17

      Tighten the factory bolts to hold the new battery into place. Reconnect the positive and negative connections and reposition the seat into its appropriate place.