I performed a pretty thorough once-over on mine since bringing it home earlier last month. It had started and run just fine, with no smoke, but the clutch was kind of grabby, and there was a hell of a racket coming from the valve cover. The valves were in spec, and the engine had great compression against the kick-starter, so I was pretty confident I had a good foundation to work with. It had started on the first kick, so I knew she liked me and wanted me to take her home. So I did. And... New wheel bearings (double-sealed bearings, re-packed with waterproof grease and re-sealed. I would seriously recommend this. New bearings frequently have a ridiculously small amount of grease in them from the factory). New chain & sprockets Re-machined & shimmed brake pedal, described earlier here. Re-welded cracked shift lever New brake pads, cleaned / polished pins Cleaned & lubed odometer drive Flushed & replaced brake fluid, Dot 4 Waterproof grease on all rear suspension pivots & links and reassemble. Soaked carb in Pine-Sol for a couple days, then careful cleaning & reassembly. 60 / 158 jetting, fuel screw 2 turns out. Home-built extended idle screw. Clutch basket fingers filed smooth, new cable. Cleaned both oil strainers. Photo of sump strainer posted here earlier. 2002 CRF450 cam chain, tensioner plunger OK. Removed non-functioning auto-decomp assembly from cam, welded those two oil holes shut in cam. New rockers, adjusted valves. Removed & cleaned airbox & drains Gordon's Mods (Uni filter, no snorkel, ground header welds). Stock muffler though. I like quiet bikes. Wrapped header & sealed w/ high-temp paint. Threads of all removed bolts were cleaned on buffer w/ wire wheel... Every bolt going into steel was greased Every bolt going into aluminum or high-temp application was Never-Siezed. New grips & handguards New footpegs ($20 eBay big 'uns) Clean & flush tank New fuel line & inline filter Denso Iridium plug Plug cap resistor replaced with copper rod New fenders (red Acerbis) Straightened bent subframe. Item had already been reinforced at the usual break point. Rotella T6 5W/40 Fresh 93 octane And... IT... IS... ALIVE!!! Baby started on the FIRST KICK! Nice and smooth, with no racket at all coming from the valve cover... just a nice sexy whir. A ride around the neighborhood (in the dark, lights work) revealed no nasty surprises. Clutch friction was good at low speed top-gear roll-on, no slipping. Great low-end torque, smooth power delivery with no obvious off-idle dead spot. SO HAPPEE!