Here's the story... Bought a stock 07 YZ 125 for 2000. Found a tricked out 08 YZ 125 for 2100 with a bored engine. Didn't want to deal with complications from the bored engine, so I did an engine/carb/CDI box swap, and sold the stock YZ 125 with the bored engine. When it was all said and done I had to do some minor repairs to the stock engine based on my inspection of the bike.
Completed Repairs:
-Shift shaft seal
-Countershaft seal
-Re-Ring (Piston and cylinder were spotless)
-Re-Jet
-Power Valve (Pins were falling out)
-Hand Cleaned the engine
In the future:
-Replace Ignition Cover Bolts (They've yielded for some reason?)
-Re-route fuel line (Kinked due to oversized tank)
-Set Race Sag (Currently is about 110 mm, static sag is about 32mm) - Target is +/- 105mm/25mm
-Wiseco Top End
-Barnett Clutch Basket
Here's the final product:





