Well, I found out what was causing my 450 to lock up. It turns out that for some reason my intake cam wasn't getting enough oil, and siezing on the journals (this time it locked up hard and jumped out of time!). Not sure why, as there is plenty getting to the exhaust, and the passages don't seem to be plugged. Maybe a weak oil pump? Anyways the journals on the head are damaged enough that the edges are furled over and I can't even remove the buckets! Am I stuck with buying a new head, or can I maybe get it built up and machined back to spec? The cam surfaces are still within spec and smooth, but look very dull. Is there a hard surface that maybe got removed? I really like this bike for the 5 minutes thet I have actually gotten to ride it!! Hopefully this is the last probs I have with it or it's down the road and back to Suzi!!