The elimination of the 125 class signaled the death of 2 stroke bikes (and in some ways a slow death to motocross for the masses)
Recall one year Ron Lechien (?) had a factory liquid cooled 125 Yamaha - might have been the first liquid cooled motocross bike we saw ... and can't be positive - but it might have been a twin cylinder
Not long after this - liquid cooled RM125's began to appear ... Mark Barnett rode one - he was so much faster during qualifying at a Mid Ohio GP the officials thought they had a timing malfunction (they ran qualifying laps at the international GP races)
good times
I saw Barnett win a supercross at the L.A. Colosseum. His physical conditioning was evident and he trounced the field on the demanding track. It was said he ran 5 miles in sand every day, then a weight session, then put 5 gallons of gas through his practice bike. I know they're all supreme athletes but that guy was a machine. Like Ricky Carmicheal.