I cleaned my oil circuit screens today.....motivated more by guilt and wanting to stop worrying about what I was imagining might be trapped in them. Turns out there was almost nothing in them. I have placed photos of the screens in "my garage." Similarly, the valves were right to spec (.006" intake and .008" exhaust). I have put about 500 miles of fairly nasty single track trial riding on this bike. I always suspected that the original owner used this bike very little and the more I tinker with it, the more I suspect he just could not start it, gave up and sold it.