What would chunks of carbon breaking loose, sound like ? Lots more fluffy carbon on my deflector, maybe I'm over oiling the valve spring wells.
Took the belt off the alternator, spun by hand CW & CCW, felt the crank, idler & cam gears, felt around in the sump, didn't find anything.
Flywheels are solid, rang each spoke, gib keys seem tight, no slop anywhere I could find. started and ran it for a couple minutes (rolls over real easy w/o the belt) belted it up, and ran again for a couple minutes, all seemed fine. I'm clueless and open to suggestions. I have shaft collars (2 piece style) on each shaft right up against the gib key, as a safety measure against falling off, and pant cuff protection.
I did find the 2 arms for the fuel tank (relocated a month ago) had a loose bolt each, so I pulled them both off completely, and reinstalled their bolts with thread sealer #2, to keep any pinhole leaks at bay. But I doubt those critters were making the sound I heard. I guess the next run will find me sitting nearby (NOT inline with the flywheels) with a string tied to the fuel control, and waiting, hopefully bored.