SCREAMIN' EAGLE BIG BORE PISTON KITS 4.500 (131) and 4.625 (135) INCH STROKE
941003492024-07-02
GENERAL INFORMATION
Table 1. General Information
Kits
Suggested Tools
Skill Level(1)
21900164A, 21900169
Safety glasses, pencil or marker, micrometer, dial bore gauge
(1) Special tools or techniques required for installation
KIT CONTENTS
Figure 1. Service Parts: Screamin' Eagle Big Bore 131/135 Piston Kits
Table 2. Kit Contents: Screamin' Eagle Big Bore 131/135 Piston Kits
Item
Qty
Description
Part No.
Notes
1
2
Piston, 131
Not sold separately
Kit: 21900169
Piston, 135
Not sold separately
Kit: 21900164A
2
2
Piston pin
22558-07
3
4
Circlip
22097-99
4
2
Ring set, standard
22000126
NOTE
Verify all contents are present in the kit before installing or removing items from vehicle.
GENERAL
Models
For model fitment information, see the P&A Retail Catalog or the Parts and Accessories section of www.harley-davidson.com (English only).
Verify that the most current version of the instruction sheet is used. It is available at: www.harley-davidson.com/isheets
Contact Harley-Davidson Customer Support Center at 1-800-258-2464 (U.S. only) or 1-414-343-4056.
Installation Requirements
WARNING
Rider and passenger safety depend upon the correct installation of this kit. Use the appropriate service manual procedures. If the procedure is not within your capabilities or you do not have the correct tools, have a Harley-Davidson dealer perform the installation. Improper installation of this kit could result in death or serious injury. (00333b)
NOTE
This instruction sheet references service manual information. A service manual for the year and model motorcycle is required for this installation and is available from:
PREPARE
NOTE
Disarm security system.
1. Remove seat. See service manual.
2. Remove main fuse. See service manual.
WARNING
To prevent accidental vehicle start-up, which could cause death or serious injury, disconnect battery cables (negative (-) cable first) before proceeding. (00307a)
3. Disconnect negative battery cable. See service manual.
4. Remove fuel tank. See service manual.
5. Remove cylinder head, cylinder, and piston. See service manual.
6. Follow procedures in service manual for inspection of parts.
Figure 2. 0.5 in. (12.7 mm)
Measuring Pistons
1. Allow piston to cool to room temperature.
2. With a pencil or marker, mark piston on each side of skirt across thrust faces (perpendicular to piston pin bore) 0.5 in (12.7 mm) from bottom edge of chamfer on piston skirt.
3. Using a micrometer at parks, measure nominal diameter of piston.
4. Use a dial bore gauge to measure piston ring travel zone in cylinder bore.
Installing Pistons
1. The pistons in this kit are not front and rear cylinder specific. Install pistons in front and rear cylinders with arrow pointing toward front of engine.
NOTE
Install rings with marking facing up. Rings with no markings can be installed either side up.
Always check piston-to-valve clearance with non-stock camshafts.
For ring compression tool, see Service Tool Instructions J06234.
Table 3. Piston Specifications
Piston
IN
MM
Fit in cylinder
0.0007-0.0020
0.017-0.050
Piston pin fit (loose)
0.0006-0.0010
0.015-0.025
Ring end gap
Top compression
0.015-0.025
0.381-0.635
2nd compression
0.015-0.025
0.381-0.635
Oil control ring
0.015+/-0.009
0.38+/-0.23
Ring side clearance
Top compression
0.0006-0.0024
0.015-0.060
2nd compression
0.0008-0.0022
0.020-0.055
Oil control rails
0.0004-0.0059
0.010-0.150
Table 4. Piston Service Wear Limits
Replace if Wear Exceeds
Item
IN
MM
Fit in cylinder (loose)
0.0045
0.1143
Piston pin fit (loose)
0.0015
0.0381
Top ring end gap
0.031
0.79
2nd ring end gap
0.032
0.81
Oil control ring rail gap
0.031
0.79
Ring side clearance
0.0035
0.089
2nd ring side clearance
0.0037
0.094
Oil control ring side clearance
0.0068
0.173
Piston Pin Circlip Installation
1. See Figure 3. Position circlip opening (1) at 12 o'clock on special tool.

Special Tool: PISTON PIN RETAINING RING INSTALLER (HD-51069-2)

2. See Figure 4. Align and insert special tool (2) with circllip into piston.
3. See Figure 5. Make sure that circlip (2) is fully seated in groove.
a. Circlip opening (1) must be at 12 o'clock position.
1Circlip opening
Figure 3. Position Circlip
1Arrow
2Special tool
3Circlip
Figure 4. Install Circlip
112 O'clock opening
2Circlip
Figure 5. Circlip Position on Piston
4. Repeat procedure for remaining circlips.
COMPLETE
1. Install cylinder heads, cylinders, and high compression pistons and rings from kit. See service manual.
2. Install fuel tank. See service manual.
3. Connect negative battery cable. See service manual.
4. Install main fuse. See service manual.
5. Install seat. After installing seat, pull up on the seat to verify that it is secure. See service manual.
6. Download the new ECM calibration using Screamin' Eagle Pro Street Performance Tuner Kit.
7. Run engine. Repeat several times to verify proper operation.
BREAK-IN RIDING RULES
Refer to the Owner's Manual to break in the motorcycle.