I also have a similar situation with some red/orange showing through the plating in the center bottom of the upper connecting rod bearing. Mine is just beginning to show through at the bottom and does not show nearly as much red/orange as the pic in the post above. I would like some seasoned opinions on whether I need to replace the crank at this point. The bike has around 100 hours on it with 70 hours on a 13.5 to 1 Wiseco piston. There almost no detectable play between the wrist pin and connecting rod. I ride mostly trails with this bike and because of this, I believe it may be due to lugging the motor in tight spots with the higher first of the MX tranny. Is it possible that when I get on the throttle without the motor spinning fast the edges of the upper connecting rod journal flex putting all of the pressure on the center which causes the wear. I'm thinking the journal gets hammered the worst at low RPM / high throttle settings. This would also explain why there is no play in the wrist pin. The motor does not make any noises that it shouldn't. If this is the case, could I start slipping the clutch and rev the bike in these situations and possibly wait untill the next top end to replace the crank?
Has anyone done this yet, who did the work, and what are the results so far? Who manufactured the SS valves? Do you have to use the '06 exhaust valves? I seem to remember seeing something about the exhaust valve stem diameter going from 5 mm to 5.5 mm for '06. I want to build a spare head, and have it ported, that will provide a reliability upgrade and be ready to install on my next teardown. Thanks, Mike