S&S, 99-06 4" stroke flywheel assembly

Standard 4" stroke. Note: Engines with strokes exceeding 4" may require S&S piston oiling jets and piston to jet clearance notches in the piston skirt to avoid contact. Note: S&S crankpins allow the use of replaceable bearing races in the lower end of the connecting rods. The first generation of S&S crankpins, in use up to 2012, were 1.500" diameter. The second generation crankpins, in use since 2013, have the larger 1.671" OEM diameter crankpins. Now S&S & OEM crankpins are identical in diameter so now S&S parts can be used to rebuild stock H-D flywheels, something that previously was not possible since H-D rebuild parts were, and are, not available. Note: Following is regarding 03-17 models. S&S has designed these flywheels to work with a Timken style sprocket shaft bearing, they will fit stock 99-02 model year and all S&S cases without modifications. Stock H-D 03-17 Twin Cam engines use the same sprocket shaft roller bearing as is used on the pinion shaft, a cost saving but weaker solution. It is possible to use the stock weak 03-17 sprocket shaft bearing kit (OEM H-D 24004-03B) with S&S flywheels in 03-17 stock cases. However, S&S feels this roller bearing will not take the side loads produced in a high performance motor. S&S will not honor any warranty claims in an application where the OEM 24004-03B/24605-07 03-17 sprocket shaft roller bearing style bearing assembly is used. To upgrade to the pre-2003 style sprocket shaft bearing fmc 978-517 JIMS conversion tool kit is available. This kit includes a tool, a Timken bearing and a steel crankcase bearing insert for one motor. Bearing inserts only are available as fmc 978-519, bearings only as fmc 508-960. Note: In any and all applications the technician must be able to judge components for their suitability in combination with the other engine components, prior to installation. It is of importance that a knowledgeable mechanic will install & make adjustments as required.

Fits: > 99-06 Twin Cam (excl. 2006 Dyna) (NU)