Check to see that there is sufficient coolant in the coolant reservoir and radiator if the engine overheats. If the level is low, check the system for leaks. If there are no apparent leaks, fill the radiator and reservoir with coolant. If you discover any leaks, or if the engine continues to overheat, have a qualified mechanic check out the cooling system for you.
Check to see whether there is a leak in the fuel tank. Turn the fuel cock lever to "OFF." Remove the fuel hose from the fuel cock. Turn the fuel cock back to the "ON" position and check the fuel flow. If you do not notice any flow of fuel, it could be that the fuel cock is damaged. Clean the fuel cock. If this still does not remedy the problem, have a mechanic investigate further.
Remove the spark plug and check the electrodes if you are experiencing ignition problems. If the electrodes are wet, clean and dry them with a dry cloth. If the electrodes are dry, attach the spark plug cap and ground to the chassis. Start the 4x4 with the electric starter. If the plug has a normal strong, blue spark, then the ignition system is normal. If the spark is weak, adjust the gap or replace the plug. If there is no spark, have a mechanic check this out for you.
Check the battery. Start the engine with the electric starter. If the engine turns over quickly, the battery is good. If the engine turns over slowly, check and clean the battery connections. Charge the battery, if necessary.
Adjust the headlight beam if they are not positioned correctly. Adjust the headlight beam adjustment screw clockwise to raise the beam, and counter-clockwise to lower the beam.
Replace the tail/brake light bulb if it has blown. Remove the nuts and washer from the bulb holder. Remove the bulb holder (together with the bulb) by turning it counter-clockwise. Remove the defective bulb from the bulb holder by pushing it inward and turning it counter-clockwise. Install the new bulb in the bulb holder by pushing it inward and turning it clockwise. Install the bulb holder (together with the bulb) by turning it clockwise. Install the washers and then tighten the nuts.There is nothing like the freedom of taking off across the dunes on a Yamaha Kodiak 400 4x4. Yamaha is a world leader in recreational bikes and ATVs. These are sturdy machines and they can take a lot of punishment, however, as with all machines with multiple moving parts, wear and tear can occur. Whether it is a problem with overheating, or a fuel leak, they are fairly simple to troubleshoot. Before taking your 4x4 in for a service, there are a few basic troubleshooting steps you can run through on your own.