Refer to Maintenance Scheduling → Regular Service Intervals → Regular Service Intervals: 2006 Sportster Models. Primary (front) chain adjustment should be checked at proper intervals and serviced as necessary. If the chain is allowed to run loose, it will cause the motorcycle to jerk when running at low speed, and chain and sprockets will wear excessively. If this happens, see a Harley-Davidson dealer or Service Manual for adjustment procedure.
Table 1. Primary Chain Adjustment: Sportster Models
COLD engine
HOT engine
1Measurement point between sprockets
2Measurement value
Figure 1. Primary Chain Vertical Free Play: Sportster Models
See Figure 2. The primary chain can be adjusted without removing the primary cover (2).
To prevent accidental vehicle start-up, which could cause death or serious injury, disconnect negative (-) battery cable before proceeding. (00048a)
1. Unthread nut and remove battery negative cable (black) from crankcase stud.
2. Remove the two hex socket screws which secure primary chain inspection cover (1).
3. Rotate sprockets to find tightest point on primary chain.
Do not adjust the primary chain tighter than specified. Running chain too tight will result in excessive wear. (00202a)
4. Loosen locknut. Turn chain adjuster screw clockwise (inward) to reduce free play or counterclockwise (outward) to increase free play. Vertical free play must fall within the limits specified.
Refer to Table 1. If vertical free play cannot be set within the limits specified, then primary chain and/or chain adjuster are worn beyond adjustment limits. Replace parts as necessary.
5. See Figure 2. When tension is set correctly, tighten locknut (6) to 27–34 N·m (20–25 ft-lbs).
6. Install primary chain inspection cover (1). Tighten hex socket screws to 4.5–6.8 N·m (40–60 in-lbs).
1Primary chain inspection cover
2Primary cover
3Clutch inspection cover
4Drain plug
5Chain adjuster screw
Figure 2. Primary Chain Adjuster: Sportster Models