There was a great discussion about Jim Pomeroy's GP Bultaco awhile back and it started me thinking about another mysterious GP winning bike. Marty Moates being the first American to win the 500cc USGP was amazing, but the fact that he won the race on a non-factory bike, to me, was even more amazing.
There is some mythology out there about this amazing piece of machinery, but I was wondering what any of you might know about the LOP YZ465?