Primary Chain Inspection
Inspect primary chain free play at proper intervals and adjust as necessary. Loose chains cause the motorcycle to jerk when running at low speed, and chain and sprockets wear excessively. If this condition occurs, see a Harley-Davidson dealer.
WARNING
To prevent accidental vehicle start-up, which could cause death or serious injury, remove main fuse before proceeding. (00251b)
  1. Remove main fuse. See Maintenance and Lubrication → Fuses.
  2. See Figure 1. Remove the two screws and the primary chain inspection cover.
  1. See Figure 2. Check primary chain tension by measuring free play.
    1. Measure free play through chain inspection cover opening.
    2. Rotate engine to move primary chain to a different position on sprockets.
    3. Measure free play several times, each time with primary chain moved so that the measurement is taken with sprockets rotated to the tightest chain position.
  2. The tightest measurement in previous step must be within the specifications. Adjust as necessary. Refer to Table 1.
Figure 1. Primary Chain Inspection Cover
Figure 2. Primary Chain Free Play
Table 1. Primary Chain Free Play Specifications
ENGINE
in
mm
Cold
3/8-1/2
9.5-12.7
Hot
1/4-3/8
6.3-9.5
Primary Chain Adjustment
NOTICE
Do not adjust the primary chain tighter than specified. Running chain too tight will result in excessive wear. (00202a)
1. See Figure 3. Loosen locknut (1).
2. Turn chain adjuster screw (2) clockwise (inward) to reduce free play or counterclockwise (outward) to increase free play. Free play must fall within specifications. Refer to Table 1.
NOTE
If free play cannot be set within specification, then primary chain and/or chain adjuster are worn beyond adjustment limits. See your Harley-Davidson dealer.
3. When free play is set correctly, hold chain adjuster screw and tighten locknut to 27–34 N·m (20–25 ft-lbs).
4. Install primary chain inspection cover with a new gasket. Tighten screws to 11.3–13.6 N·m (100–120 in-lbs).
5. Install main fuse.
1Locknut
2Chain adjuster screw
3Transmission chaincase drain plug
Figure 3. Primary Chain Adjuster: Sportster Models