SCREAMIN' EAGLE PRO 10.5:1 COMPRESSION, 3.875 INCH BORE PISTONS
J043922009-03-05
GENERAL
NOTE
Always check piston-to-valve clearance when using non-stock camshafts.
All dimensions listed on these instructions are in inches.
High compression piston applications require installation of appropriate compression release in cylinder heads.
The pistons in this kit require the use of a plated piston pin (22455-03) only.
Kit Numbers
22143-08A, 22144-08A
Table 1. Kits
Kit
Application
22144-08A
Standard, 3.875 in. (front & rear)
22143-08A
+0.010 (front & rear)
Models
These kits fit 2007 and later Twin Cam models equipped with the following items:
  • Cylinder Heads: Original equipment cylinder heads.
  • Cylinders: Screamin' Eagle Pro 3-7/8" Big-Bore cylinders.
  • Flywheels: 2007-later original equipment 4-3/8" stroke flywheel assembly or Screamin' Eagle Pro 4-3/8" stroke flywheels..
NOTE
This engine-related performance part is intended for high-performance or racing applications and is not legal for sale or use on pollution-controlled motor vehicles. This kit may reduce or void the limited vehicle warranty. Engine-related performance parts are intended for the experienced rider only.
Additional Parts Required
NOTICE
You must recalibrate the ECM when installing this kit. Failure to properly recalibrate the ECM can result in severe engine damage. (00399b)
NOTE
ECM recalibration is required, which can be performed with the Screamin' Eagle Race Tuner Kit (Part Number 32107-01F). See a Harley-Davidson dealer.
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 your model motorcycle is required for this installation and is available from a Harley-Davidson Dealer.
Kit Contents
See Figure 3 and Table 4 .
INSTALLATION
WARNING
To prevent accidental vehicle start-up, which could cause death or serious injury, disconnect battery cables (negative (-) cable first) before proceeding. (00307a)
WARNING
Disconnect 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)
1. Refer to the Service Manual and follow the instructions given to remove the seat and disconnect the battery cables, negative cable first.
WARNING
When servicing the fuel system, do not smoke or allow open flame or sparks in the vicinity. Gasoline is extremely flammable and highly explosive, which could result in death or serious injury. (00330a)
2. Refer to the ENGINE: STRIPPING MOTORCYCLE FOR SERVICE and TOP END OVERHAUL, DISASSEMBLY sections of the Service Manual for cylinder head, cylinder and piston removal procedures.
3. Follow the procedures in the ENGINE: SUBASSEMBLY SERVICE AND REPAIR, TOP END/ CYLINDER/ UPPER CONNECTING ROD sections of the Service Manual for inspection of parts.
4. See the ENGINE: SUBASSEMBLY SERVICE AND REPAIR, CYLINDER section of the Service Manual for boring and honing instructions.
NOTE
Install piston rings having dots or bevels with the dots or bevels facing UP. Rings with no markings can be installed either side up.
Piston dimensions to be measured 0.38 inches above the lowest part of the skirt.
5. The pistons in this kit are not front and rear specific. Install the pistons in the front and rear cylinders with the arrow on top of the piston pointing towards the front of the engine.
6. Refer to the ENGINE: TOP END OVERHAUL, ASSEMBLY section of the Service Manual for piston, cylinder and cylinder head installation procedures.
Table 2. Piston Clearances
Piston:
Clearance (in.)
Fit in cylinder
0.0015-0.0025
Compression ring gap:
  • Top
0.009-0.015
  • Second
0.019-0.029
Oil control rail gap
0.010-0.030
Table 3. Piston Service Wear Limits
Piston:
Wear Limit (in.)
Fit in cylinder
0.005
Compression ring gap:
  • Top
0.025
  • Second
0.039
Oil control rail gap
0.030
Piston Pin Retaining Ring (Circlip) Installation
NOTE
Circlip gap must be at 12:00 or 6:00 position when installed.
7. See Figure 1. Insert the open end of the circlip (1) into the notch (3) on the groove (2) around the piston pin boss so that the gap is at the 12:00 or 6:00 position when installed.
1Circlip
2Notch
3Groove
Figure 1. Circlip and Piston
1Thumb orientation
2Circlip 85% seated
Figure 2. Install Circlip
8. See Figure 2. Position your thumb (1) as shown, and press firmly until approximately 85% of the circlip (2) is seated in the groove.
9. Being careful not to scratch or mar the piston, use a small-bladed screwdriver to wedge the circlip into the remainder of the groove. Repeat for the remaining circlips.
NOTE
Make sure the piston circlip is fully seated, or ENGINE DAMAGE WILL OCCUR.
10. Refer to the ENGINE: ASSEMBLING MOTORCYCLE AFTER STRIPPING section of the Service Manual for final re-assembly procedures.
NOTE
Always follow the break-in procedure outlined in the appropriate Owner's Manual after rebuilding an engine.
SERVICE PARTS
Figure 3. Service Parts: Screamin' Eagle Pro 10.5:1 Compression, 3.875 Inch Bore Pistons
Table 4. Service Parts Table: Front and Rear Piston Kits
Kit
Item
Description (Quantity)
Part Number
Kit 22144-08A
Piston Kit
(Standard)
1
Piston (front, standard)
Not sold separately
2
Piston (rear, standard)
Not sold separately
3
  • Ring set, standard
22457-03
4
  • Piston pin
22455-03
5
  • Circlip (2)
22097-99
Kit 22143-08A
Piston Kit
(+0.010)
1
Piston (front, +0.010)
Not sold separately
2
Piston (rear, +0.010)
Not sold separately
3
  • Ring set, +0.010
22459-03
4
  • Piston pin
22455-03
5
  • Circlip (2)
22097-99