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[TN]

i have an 08 fltr, hd 103 kit, stock heads, redshift 577 cams, pro tapered adj. push rods. 2/1 supertrapp with 20 disk. tuned with directlink-auto tune on the dyno using wideband o2 sensors. have had this setup for some time now logged around 12k miles er so. recently heard a clunking sound and thought it was not mechanical started searching. when ya fire it up and warms up a bit you can hear it at idle. using a stethoscope the sound emitted from the air intake (air cleaner off) it didn't vary.
tearing it down there is no evidence of anything out of line. heads apart, cylinders off, and cams out. i do have a new set of s & s lifters to put back in. i hate to assemble the engine without finding the root cause.

the best way to describe the noise is a clunk or knock 30 seconds er so after she fires up. still ran good.
i do have an indy performing the work, as he's not sure of the cause.



suggestions please


TN

[Unbalanced]

2 things I would check:

Have you checked to see that the starter is disengaging correctly? 

Also have you checked that the compensating nut is not loose either.   This typically shows itself the most at idle / neutral.

[Godeater]

Hows the old front motor mount, as the idle comes down after cold start and you get more of a lope the motor isnt bottoming out or topping out because of bad mount is it?  Had this happen with stocker once.

[Ride n Shine]

You have big, open cams, big pistons with a longer stroke and often that knock like sound is induction noise, the first Harley I hot rodded done the same thing and stressed the chit out of me for some time but after talking with a few guys that built big motors I was told that was what it was as I could only hear it at carb. Mine did it hot or cold but until I relaxed a bit I was sure it would blow any second when it was cold and that bike is still running 45k later, Paul (the guy that owns her now) or I ride gently. Hope this helps a little.