.004 and .007

I installed the shafts in these knuckle flywheels (only after we double-checked the quality of the centers and run-out of each shaft.)  Guess what?  The centers needed fixing.  Some dudes might have just tossed the original H-D shafts, when they didn't really see what the problem was.  Others may have just assembled everything and trued it up, not realizing they were off, 'cause their center was damaged.  Gotta really check this shit . . . new in the package, or used.  Check it.

I installed the shafts (with a new key in one) and put them in the truing stand using the "special long center" I had made to reach the short sprocket shafts.  I checked the run-out of the far edge of the outside face of each flywheel.  S&S Cycle likes .007 or less, so I always use that as a guideline.  One had +020 and the other +010.   If you can visualize this: I take them out and put the end of the shaft (down on a lead plate) with the "high side" down on the plate.  I strike the flywheel on the top edge, carefully with a non-marring lead hammer.  What I'm attempting to do here is make the shaft more perpendicular to the flywheel.  Check run-out again in truing stand.  You can adjust your run-out in this fashion correctly.  If it doesn't move after a couple strikes I quit.  It takes time, but now you can assemble the flywheels and true the crank pin - I believe you will have a smoother, stronger and longer lasting rotating assembly. 

NOTE: If it still has too much run-out, I remove the shaft, remove the key and gently lap the shaft to the taper a bit (not too much) - then wipe clean, clean with brake kleen, then reassemble.  You have to get this in the .007-.010 range for best result.  Then try a different shaft if you can't get it, and make sure the nut face(towards the flywheel) is true, an out-of-true face can kink the shaft too.