Trying to use my brain . . .

McFarland made me a new longer precision center so I can check run-out on short parts.  I've got a 60s Sporty motor of Polgreen's that we're rebuilding from parts.  I picked out the nicest lookin' set of flywheels and started checking each 1/2 for run-out like I always do.  The left (sprocket-side wheel) had like +.025-.030 run-out on the face.  The shaft itself was dead nuts perfect.  I popped it apart, and it didn't really have the right key . . . but, the tapers looked ok.  We tried it with the new key, but still has +.025.  I mean zero run-out would be nice, but Lakeshore H-D says +.007 is acceptable way out on the face.  ABOVE PHOTOs:  We even checked the shaft flange and the nut for run-out.  If you think about it . . . if the nut was off, it could possibly "kink" or pull the shaft possibly.  Diagnosis:  Shaft ok - Taper in flywheel is damaged or just machined wrong.  We checked out his other set of flywheels, and they are much better, +.005 before we trued each 1/2 - we'll use those.  Maybe all that run-out wouldn't make much of a difference, but it would probably wear out your Timken prematurely, or vibrate at certain speeds, or just be a mutt of a motor with not much power.
Just keepin' old Harley's alive . . . everyday.

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