Honda recommends that you check and adjust your valve clearance every 8,000 miles. Valves do wear, and as such need to be checked periodically. Valves that have excessive clearance may cause loud tapping noises, excessive valvetrain wear and poor mileage, while valves with insufficient clearance can cause poor compression, poor mileage, and valvetrain damage from overheating. Valves with correct clearance cause the engine to run smoother and with less vibration.
Fortunately, while it may look a bit scary, checking and adjusting your valves is extremely simple on the Goldwing, and well within the capabilities of even the novice mechanic. The valves are hanging out on each side of the engine, and are easily accessible.
The valve clearances must be measured and adjusted when the engine is dead cold - like it is after the motorcycle has been sitting overnight. Adjusting valves when the engine is warm will result in improperly adjusted valves.
Adjusting the valves is a good time to also change the oil. Because the valvetrain is immersed in oil, there will be oil inside the valve covers. I prefer to drain the engine oil, adjust the valves, then when finished, refill the engine with new oil. For details on this procedure, see How to change your engine oil
1. Remove the stator bolt cover on the rear of the stator. This will expose the bolt used to rotate the engine.
2. Once the cover is removed, clean the threads and put it aside.
3. Using a large flat blade screwdriver, remove the timing wheel cover from the top left side of the engine. This will expose the timing wheel. Once removed, clean the threads and put it aside.
4. Remove the four bolts holding each timing cover. The bolts do not have to come completely out of the cover in order to remove it, but you may find it easier if you do remove them fully.
5. The valve covers can be maneuvered off the motorcycle by pulling them rearward through the crash bars. Note that I have a pan on the floor to catch any oil that may spill out. Once the valve covers are off, I use shop towels to soak up any residual oil inside the valve area, to prevent drips on the floor.
6. The right side valve cover comes off the same way, however it has to be maneuvered around the fuel pump. They can come out easily, so if you are stuck, push it back in and try again using a different angle.
7. Remove the valve cover gaskets. If the gaskets are in reasonable condition, they can be reused. I replaced mine with a set from partsnmore.com
- at $12 apiece. The same gasket fits both the left and right sides.
8. Fit a socket and ratchet onto the stator bolt on the back of the engine. It is VERY important that you rotate the engine CLOCKWISE only - as if you were tightening the bolt. Rotating the engine backwards can cause the stator bolt to loosen off! Try rotating the engine so that you get a feel for it. You will be rotating against the compression of the cylinders - if you have a hard time turning it, try turning it slower, or remove all the spark plugs, which will eliminate the compression resistance.
9. View the timing wheel as you rotate the engine. Rotate the engine until you see the "T" come into view with the "1" below it. The two horizontal lines on either side of the "T" should match up exactly with the two lines on the engine case, on either side of the opening, as shown. We now need to make sure that cylinder number 1 is at Top Dead Center.
Sitting on the motorcycle facing frontward, the number 1 cylinder is the right side frontmost cylinder. Number 2 is the left side frontmost cylinder, 3 is the rearmost cylinder on the right side, and 4 is the rearmost cylinder on the left side.
10. Grab the intake rocker arm (the top one) on the number 1 cylinder, and push it back and forth. You should feel very slight movement - so small you may not be able to see, but you can feel it. If you're not sure if you're feeling movement or not, try the intake rocker on cylinder number 3 (next to it). One of the two will move, and one will be solid, with no movement.
11. Also check the exhaust rocker arm (the bottom one) on the number 1 cylinder. You should feel very slight movement on this one as well. If you do not feel movement on either number 1 cylinder rocker arms, and instead you feel movement on the number 3 intake rocker arm, then go back to step 9 and rotate the engine once (360 degrees) until the "T" lines up again. At this point cylinder 1's rocker arms should have free play, and cylinder 3's intake rocker arm should be solid.
12. Put the correct width feeler gauge between the valve stem and the rocker arm. The correct feeler gauge was included in the tool kit originally supplied with the motorcycle. If it is missing, you can purchase them inexpensively at any automotive store. The feeler gauge should move easily between the valve stem and rocker arm, with just the slightest amount of drag.
GL1000: All valves: 0.1 mm (0.004 inches)
GL1100: Intake valves: 0.1 mm (0.004 inches), Exhaust valves, 0.13 mm (0.005 inches)
GL1200: Not required! The GL1200 has hydraulic valve lash adjusters to automatically ajust valve clearances.
13. If the valve clearance needs to be adjusted, loosen the locknut.
14. Adjust the screw in the middle of the locknut until the correct amount of drag is felt on the feeler gauge.
15. While holding the screw in place, retighten the locknut. When the locknut is tightened, re-check the clearance with the feeler gauge again, to ensure it wasn't altered when the locknut was tightened.
16. Repeat the procedure on the exhaust valve of the number 1 cylinder, the exhaust valve of the number 3 cylinder, and the intake valve of the number 4 cylinder. Once these four valves have been completed, rotate the engine once (360 degrees) until the "T" lines up again. At this point, repeat the adjustment procedure on both the intake and exhaust valves on cylinder 2, the intake valve on cylinder 3, and the exhaust valve on cylinder 4.
Cylinder 1 Intake
Cylinder 1 Exhaust
Cylinder 3 Exhaust
Cylinder 4 Intake
Cylinder 2 Intake
Cylinder 2 Exhaust
Cylinder 3 Intake
Cylinder 4 Exhaust
17. If you are reusing the valve cover gaskets, inspect and clean the gaskets, and reinsert them into the valve covers.
18. If you are using new gaskets, coat them lightly with engine oil, and insert them into the valve covers.
19. Maneuver the valve covers back into place, and check that the gaskets are flush between the valve cover and the engine, and have not twisted or bulged out of place.
20. Tighten each bolt on the covers to 8 ft/lbs torque.
21. Reinsert the timing wheel cover and tighten into place. Make sure you don't cross-thread the cover. You may want to start it using your fingers to ensure it is not cross-threaded, then use the screwdriver to tighten it. Don't forget this step, or you will find that your Goldwing will turn into a giant oil fountain when it is started up!
22. Replace and tighten the stator cover. Again, you may want to start this by hand, then use a wrench to tighten.
23. If you drained the engine oil before starting the procedure, make sure you refill the crankcase with oil before starting the motorcycle!
Anytime you have adjusted the valves, it is a good idea to resynchronize the carburetors, as the sensitive carburetor sync adjustments can be altered by minute timing differences in the intake valves caused by valve gap adjustment.