If you are hearing excessive clicking sounds coming from your valve tappets or if your Sportster is not performing up to its normal level, it may mean your tappets are too loose or too tight. Here's how to adjust the tappets on your Harley-Davidson Sportster with cast-iron cylinders heads. It is a relatively easy adjustment, requiring a few simple tools and about an hour or less of your time.
Tools and Equipment You Will Need
- ½ inch open end wrench
- 7/16th inch open-end wench
- ratchet
- spark plug socket
- a flathead screwdriver
- something to elevate your motorcycle, such as a jack
- a set of hooks made from solder or a coat hanger
- a bungee cord
Procedure
- Make sure your Harley-Davidson Sportster engine is turned off and is not hot.
- Remove any bracket or covers that are blocking the view of the pushrods.
- Jack up the back of your motorcycle so the rear end is elevated.
- Remove the spark-plug wires; then use your ratchet and spark plug socket to remove the spark plugs.
- Disengage the clutch, wrap the bungee cord around the handgrip, and clutch lever in order to keep the clutch disengaged.
- Run through the gears by rotating the rear wheel with your hand; operate the gearshift with your other hand, going through second, third, until you get to fourth gear. Now remove the bungee cord.
- Use your screwdriver to lower the pushrod cover spring retainer; then remove the keeper. Note: You are working on one cylinder at a time.
- Push the rod covers up to collapse them.
- Fabricate a set of hooks to hold up the pushrod covers. (You can use a piece of solder or a coat hanger; it must be long enough to reach down to the ends of the pushrod covers and up to tops of the cylinder heads.) Attach the ends of the hook underneath the rod covers; then strap the other ends up over the top of the valve cover.
- Use the kick starter or your hand to rotate the rear wheel to move the tappets up and down. You will notice that on each cylinder, when one valve is open, the other valve is closed. So if you are going to adjust the tappet on an intake valve, it will be closed when the cylinder's exhaust valve is open.
- Let us suppose we are going to adjust the tappet on the front intake valve. Rotate the engine until the front intake valve is fully closed (the exhaust valve on the front cylinder will be fully open).
- On each valve, you have a pushrod, adjustment screw, lock nut and tappet. To adjust the tappet, you will need the ½-inch open-end wrench and the 7/16ths open-end wrench. Use the ½-inch wrench on the adjustment screw and the 7/16ths wrench to loosen up the lock nut.
- After it is loose, turn the adjustment screw counter-clockwise with your fingers until you cannot rotate the pushrod at all. Then back this off a little by turning the pushrod clockwise until you can just move it. (The factory recommendation is that you are able to turn the pushrod all the way around, 360 degrees.)
- If you are adjusting an exhaust valve, you will turn the adjusting screw so that you back off one "flat" of the screw further. If you are adjusting an intake valve, you will back off one "point" of the screw further.
- Proceed to tighten down the lock nut 8-10 lbs. ft. - not very tight. If the pushrod has no up and down movement, you can turn it slightly, and it is snug against the adjustment screw, then you have adjusted the tappet properly. You will "get a feel" for the procedure and how tight the pushrod should be against the adjustment screw after making these tappet adjustments a few times.
- When you are finished working on all of the tappets you would like to adjust, take the solder (or coat hanger) hooks off.
- Next, you are going to center the pushrod covers. Use a flathead screwdriver to reveal the upper part of the pushrod. Center the top part and then the bottom section of the pushrod cover. Then use your flathead screwdriver to re-install the keeper. Do this on any and all cylinders you worked on and adjusted.
- After you have centered all the pushrod covers -- put the bike in neutral, take it off the jack, reinstall the spark plugs, and re-attach the spark plug wires. Now you are finished.