How to Time a Harley-Davidson Motorcycleby Michelle Schaefer
Checking the timing on your Harley-Davidson motorcycle every 5,000 miles plays an important role in a comprehensive maintenance routine. As a Harley-Davidson engine ages, you must adjust the ignition timing to compensate for the wear of internal engine parts. Setting the timing correctly keeps your motorcycle running smoothly and efficiently. Maladjusted timing may result in sluggish performance, poor fuel economy and possible damage to internal engine components. Setting the timing is relatively easy and ensures the maximum life from the engine.
Remove the crankcase timing plug using an Allen wrench, and expose the timing hole. The timing hole is located on the primary chain case side of the motor on the engine block and capped with a solid hex-head plug. Install a clear plastic timing hole plug to prevent oil splash.
Connect the positive terminal of an inductive timing light to the positive battery terminal of the motorcycle. Connect the negative terminal of the timing light to the negative terminal of the battery. Connect the inductive pickup probe of the timing light to the front cylinder spark plug wire.
Start the engine, and run it at idle. Point the timing light into the timing inspection hole. If the ignition is properly timed, the timing bar will align with the circular timing reference mark. The reference marks on a correctly timed engine will appear as a vertical bar through the center of the circle. Some models only have a timing reference mark on the flywheel of the motor; on these models, the engine is correctly timed when the reference mark is visible in the timing inspection hole.
Remove the timing cover from the right side of the motor with a Phillips screwdriver or Allen wrench, depending on your specific model. Loosen the the timing plate screws with a slotted screwdriver, and turn the timing plate to adjust the timing. Recheck the timing marks with the timing light. Tighten the timing plate screws, and install the cover.
Shut off the engine, and remove the timing light. Remove the clear plastic timing hole plug, and install the solid plug in the hole.
- The reusable clear plastic timing hole plug is available from your local Harley-Davidson dealership. The plugs are not interchangeable between production models; purchase the one made specifically for your bike.
- Exhaust fumes are toxic; work only in a well-ventilated area.
- Exhaust pipes become extremely hot during, and for some time after, engine operation. Severe burns may result from contacting the pipes with exposed skin. Avoid contacting the pipes with test equipment wires or other tools.
Items you will need
- Allen wrench
- Clear plastic timing hole plug
- Inductive timing light
- Phillips screwdriver
- Slotted screwdriver
- "Harley-Davidson Sportsters, 1959 to 1985"; Clymer; 1986
- motorcycle image by Greg Pickens from Fotolia.com