SCREAMIN' EAGLE 4-1/8 INCH BOLT-ON PISTON KIT
J062822020-08-20
GENERAL
Kit Numbers
21900079
Models
For model fitment information, see the P&A Retail Catalog or the Parts and Accessories section of www.harley-davidson.com (English only).
Installation Requirements
NOTICE
You must recalibrate the ECM when installing this kit. Failure to properly recalibrate the ECM can result in severe engine damage. (00399b)
NOTE
Proper installation of this kit also requires the use of Digital Technician™ at a Harley-Davidson dealer.
Proper installation of this kit also requires ECM recalibration using EFI Race Tuner Kit. Refer to Screamin' Eagle Pro Catalog or contact a Harley-Davidson dealer.
WARNINGRider 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 your model motorcycle is required for this installation. One is available from a Harley-Davidson dealer.
Kit Contents
This engine-related performance part is intended for high performance or racing applications. Not legal for sale or use on pollution controlled motor vehicles. This kit reduces or voids the limited vehicle warranty. Engine-related performance parts are intended FOR THE EXPERIENCED RIDER ONLY.
INSTALLATION
| 1. | Raise the motorcycle. NOTE Disarm security system. | |
| 2. | Remove seat according to the instructions in the service manual. | |
| 3. | For Touring Models: Remove left side saddlebag. Remove main fuse. Refer to the service manual. For Softail Models: Remove main fuse. Refer to the service manual. For Dyna Models: Remove electrical caddy cover and main fuse. Refer to the 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) WARNINGDisconnect negative (-) battery cable first. If positive (+) cable should contact ground with negative (-) cable connected, the resulting sparks can cause a battery explosion, which could result in death or serious injury. (00049a) | ||
| 4. | Disconnect negative battery cable. | |
| 5. | Refer to the appropriate sections of the service manual for cylinder head, cylinder and piston removal procedures. | |
| 6. | Follow the procedures in the service manual for inspection of parts. |  Figure 1. 0.394 in. (10.0 mm) |
Measuring Pistons
- Allow the piston to cool to room temperature.
- With a pencil or marker, mark the piston on each side of the skirt across the thrust faces (perpendicular to the piston pin bore) 0.394 in (10.0 mm) from the bottom edge of the chamfer on the piston skirt.
- Using a micrometer at the marks, measure the nominal diameter of the piston.
- Use a dial bore gauge to measure the piston ring travel zone in the cylinder bore.
Installing Pistons
- The pistons in this kit are not front and rear cylinder specific. Install the pistons in the front and rear cylinders with the arrow pointing toward the front of the engine.
NOTE
Install rings with markings facing up. Rings with no markings can be installed either side up.
4.125 in cylinders use the same cylinder base and crankcase dowel O-rings as the stock 4.00 in CVO cylinders.
Always check piston-to-valve clearance with non-stock camshafts.
For ring compression tool, see Service Tool Instructions J06234, Ring Compressor Band Tool #HD96333-106 (4-1/8).
Table 1. Piston Specifications
ITEM | IN. | MM |
|---|---|---|
Fit in Cylinder | .001-.0027 | .025-.069 |
Top Ring End Gap 2nd Ring End Gap Oil Control Ring Rail Gap | .009-.019 .016-.026 .001-.030 | .220-.470 .400-.660 .250-.770 |
Top Ring Side Clearance 2nd Ring Side Clearance Oil Control Ring Side Clearance | .0002-.0025 .0004-.0026 .0015-.0074 | .005-.063 .011-.066 .037-.187 |
Piston Pin Fit (Loose) | .0006-.0009 | .014-.024 |
Table 2. Service Wear Limits
ITEM | IN. | MM |
|---|---|---|
Fit in Cylinder (Loose) | .0040 | .102 |
Piston Pin Fit (Loose) | .0013 | .033 |
Top Ring End Gap 2nd Ring End Gap Oil Control Ring Rail Gap | .029 .036 .030 | .737 .914 .762 |
Top Ring Side Clearance 2nd Ring Side Clearance Oil Control Ring Side Clearance | .0033 .0034 .0083 | .083 .086 .210 |
Piston Pin Circlip Installation
| 1. | See Figure 2. Insert open end of circlip (1) into notch (2) on groove (3). | |||||||||||
| 2. | See Figure 3. Place thumb on piston (1). Press firmly until approximately 85% of circlip (2) is seated in groove. | |||||||||||
| 3. | Use a small blade screwdriver to wedge circlip into remainder of groove. Do not scratch or mar piston. Repeat for remaining circlips. NOTE Make sure that the circlip is fully seated for proper installation. | 
Figure 2. Circlip and Piston 
Figure 3. Install Circlip | ||||||||||
| 4. | Install cylinder heads cylinders, and high compression pistons and rings from kit. Refer to appropriate sections in service manual. |
FINAL ASSEMBLY
| 1. | Install fuel tank according to the instructions in the service manual. | |
| 2. | For Touring Models: Install main fuse, left side cover and left side saddlebag. Refer to the service manual. For Softail Models: Install main fuse. Refer to the service manual. For Dyna Models: Install main fuse and electrical caddy cover. Refer to the service manual. | |
| 3. | See the service manual. Install seat. After installing seat, pull up on the seat to make sure that it is secure. | |
NOTICE You must recalibrate the ECM when installing this kit. Failure to properly recalibrate the ECM can result in severe engine damage. (00399b) | ||
| 4. | Refer to Screamin' Eagle Pro Catalog or contact a Harley-Davidson dealer. | |
| WARNING After installing seat, pull upward on seat to be sure it is locked in position. While riding, a loose seat can shift causing loss of control, which could result in death or serious injury. (00070b) | ||
| 5. | Run engine. Repeat several times to verify proper operation. |
BREAK-IN RIDING RULES
Refer to the Owner's Manual to break in the motorcycle.
SERVICE PARTS
Figure 4. Service Parts: Screamin' Eagle 4.125 Inch Bolt-On Piston Kit
Table 3. Service Parts: Screamin' Eagle 4.125 Inch Bolt-On Piston Kit
Kit | Item | Description (Quantity) | Part Number |
|---|---|---|---|
21900079 Standard | 1 | Piston, standard | Not Sold Separately |
2 | Piston Ring Set, standard (2) | 22000051 | |
3 | Pin, piston (2) | 22100001 | |
4 | Circlip, piston pin (4) | 22097-99 |