How to Adjust the Valves on a 2001 Yamaha Kodiakby Chris GillilandUpdated November 07, 2017
Items you will need
10 mm, 12 mm and 17 mm sockets
5 mm and 6 mm Allen wrench
Spark plug socket
.0039 inch and .0079 inch feeler gauges
10 mm box wrench
The gap between your 2001 Yamaha Kodiak's valves and the rocker arms that move them is called valve clearance. This gap is necessary to accommodate the expansion of the metal valves as they are heated during regular operation. Your Kodiak's valve clearance must fall within a certain specification to prevent premature engine failure. If the clearance is less than specified, the valve will overheat and eventually fail. Too much clearance, however, will wear away at the rocker arms. Routine valve adjustments will compensate for the changes in the valves' clearance caused by normal usage.
Remove the seat from your Kodiak, using the latch on the rear of the seat. Pull the gas tank side covers off your Kodiak's frame. Unscrew the gas cap. Unscrew the bolts at the base of the gas tank, using a 10 mm socket and a socket wrench, then lift the gas tank's cover off your Kodiak. Unscrew the gas tank's mounting bolts with a 10 mm socket. Lift the tank off your Kodiak's frame and unplug the gas line.
Unbolt the front rack and bumper from your Kodiak, using a 12 mm socket and a socket wrench. Pull the plastic rivets out of the front fender's center panel, then pull the panel away to access the headlights' wiring. Unplug the headlights from their connectors. Unbolt the front fender from your Kodiak's frame, using a 5 mm Allen wrench and a 12 mm socket.
Unplug the spark plug cable from the left side of the motor. Unscrew the spark plug with a spark plug socket and a socket wrench. Remove the intake tappet cover from the top of your Kodiak's motor and the exhaust tappet cover from the bottom of the motor, using a 6 mm Allen wrench.
Remove the pull-start cover from the left side of the motor, using a 10 mm socket and a socket wrench to access the timing port and the motor's crankshaft. Unscrew the plug from the timing port, positioned to the right of the crankshaft, using a flat screwdriver.
Place a 17 mm socket and a socket wrench over the end of the crankshaft. Turn the crankshaft counterclockwise until a "T" mark is centered over the notch on the bottom of the timing port.
Slide a .0039-inch feeler gauge between the intake valve and its rocker arm on the top of the motor. The gauge should slide between the valve and rocker arm with a small amount of resistance. If there is no resistance, the clearance between the valve and the rocker arm is too great. If the gauge cannot be inserted between the valve and the rocker arm, rotate the crankshaft one complete turn and take another measurement. If the gauge cannot be inserted after rotating the crankshaft, the valve clearance must be increased.
Loosen the lock nut from the adjuster bolt on the top of the rocker arm, using a 10 mm box wrench. Turn the adjuster bolt clockwise with a flat screwdriver to reduce the valve's clearance or turn it counterclockwise to increase the valve's clearance. Check the valve clearance again with a .0039-inch feeler gauge. Hold the adjuster bolt steady with your flat screwdriver and tighten the lock nut against the rocker arm with your 10 mm box wrench.,
Inspect the exhaust valve's clearance, using a .0079-inch feeler gauge. Follow the same method used to inspect and adjust the intake valve's clearance.
Reassemble your Kodiak, following the reverse order of removal.
- "The Professional Motorcycle Repair Program"; Professional Career Development Institute; 1995
- "Yamaha YFM400FAN Service Manual"; Yamaha Motor Corp.; 2001