For those that hang out on the IronHead list - my apologies for the repeat -

Here's the symptoms on my '98 883/1200, N4, S/E valvespring XL:

Thunking sound, most pronounced @ idle, souunds like it's at half engine speed. NO vertical play in rods, pinion bearing "looks" OK ( haven't miked it yet ) - crank sprocket was tight, and low-oil pressure light flickering at idle.

Disassembled the oil pump for insection yetsterday, and this is what I found:
<see pics>
A gouge in the oil-pump "cap" ( don't know the proper name for the bottom part of the oil pump ) and some slight marks ( not discernible when dragging a fingernail across them ) on the supply/scavenge separator plate.

I've got the cases split, but, haven't pressed the flywheel assembly from the left case half yet - Before I go this far - I thought I'd solicit opinions from the collective as to possible causes.

Thanks -

Ray Kimbro - 2 XLs - both in pieces.

Lifters are new - stock HD - less than 500 Miles. Cams/bushings seem fine - though w/the profile of the N4s & the higher-pressure springs,there's been a bit of clacking since they were first installed about 20K miles ago.

There's a little ( much less than the .025" wear limit in the book ) side-side play between the female rod and the flywheel thrust washers - absolutely NO side-to-side "rocking" play.

The rocker-arm bushings have no vertical play - I'm kinda running out of ideas for things to check.

Any thoughts are appreciated -

Ray

Ray,
Have you checked the cam end-play? Shimming the cams on Natasha took a majority of the noise from the valve train. Outside of that, I dunno. Wrist pin bushings?

Sam

Hey Sam - good to hear from you.

The cams do indeed have some end play - I'll throw the cover on the right case half and mike 'em out tonight.