The 8mm head stud just below the exhaust port is sitting proud.  A tool bit snags on the edge of the stud.  The internal threads in the aluminum head are giving up.  I discuss this in another post on head fasteners and how to repair them.

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1665791582

See how the tool bit snags on the edge of the stud.  The stud is proud about .007”.

The top of the piston was pristine.  Almost no carbon accumulation after more than 14,000 miles.  The flat-top piston really runs clean.

My cylinder had telltale marks in the bore.  Although you can’t catch your fingernail on any of the marks, and a very light honing will most likely clean them up, I’m not likin the look of this.  It’s lookin like an issue with debris from the crank case.

The piston looks great.  Not a blemish anywhere.  You can still see and feel the tool marks from the manufacturing process.  Piston rings look good too, but I suspect they are the cause of my lower than anticipated compression pressure.  Wrist pin is in good shape.

The pin bores looked good, a few superficial marks from pin removal.

Left-hand bearing play was about .0025” up & down.  That’s a bit more than it was.  When I installed the engine, it was .0020”.

The right-hand main bearing play was .0005”.

This whole project was essentially a recovery from my Big Bore Flat-Top engine 5th gear failure.  On the Big Bore engine, 5th gear pitted badly, and chunks of the gear teeth ended up in my cylinder.  Those steel particles chewed up the cylinder and the marks in the cylinder, although much deeper and far from superficial, looked similar to the marks I am seeing in this engine’s cylinder.  A gear inspection was in order.

I took a long, hard look at 5th gear on the input shaft.  It looked perfect.  But because of the failure on the Big Bore, I have been restricting the WOT operation on this 94mm Flat-Top engine.  These days, I reserve the WOT stuff for 1st through 4th.  So, it seemed prudent to also take a long, hard look at 4th gear.

Oh my!  Lucky I took a look.  My 4th gear was pitted severely.  Smaller engine, a little less steam, but the gears still can’t handle the torque.