I recently met a guy, with a barn full, and 2 trailers, of air cooled mx bikes. Maybe around 150? Mostly all yellow to my disappointment. So that got me going on picking 1. A 250 at least, he does have a 500 Can Am, but parts availability is very important. Whatever I end up with, will probably get trashed monthly. I do plan on training and racing it, near religiously! He has a couple Hondas, too bad I know about the forks. Never a big fan of the early mono shocks. So that leaves the frigging RM's. How are parts for the 77 to 80 250's? Maybe a little more bore? What big bores were good in that same era? Next weekend I will go with a pocket full of 20 dollar bills!