I THINK 6600 AND THE PREVIOUS OWNER STATED IN ORIGINAL EBAY ADD IF YOU ASK THIS OWNER THEN HE WLL TELL YOU BUT YOU HAVE TO ASK FIRST AND HE SAYS ITS A EASY FIX
HERE WHAT I GOT FROM A QUESTION I ASK ABOUT THE GEAR BOX
I am selling the ossa, only because, i have been chasing a yz 250 a and b for a lot of years, i was sponsored on one in 1973, l love the ossa it is a great bike and very light, i have spoken to a chap who owns an ossa, neil daymond ownes an ossa, my friend feels and i feels that there isn`t much wrong with it, the gears shilfs well has good spring tenion, and Alex in Amercia owns ossa and he has all the parts to fix that issue with gear spring selectors, they click up and down very well. but when it is in nutural area, thereis not much tenion, the engine sound very tight, it is a great bike, i would really like someone to own it and race it, we don`t see them around, when i get my yz it will be raced.
if you what it don`t hesitate it is a lovely bike.