1979 Yamaha XS 650 SF "rear main seal transmission replace" Questions

...rear of the bike off the ground. Now, you can shift the transmission and watch the actions of the shifter cam. Pay particular attention to the 5th gear shifter fork. See how much "play" the fork has ...

rear fender from exhaust pipe factory carb settings and it blows oil all over the fender,runs fine,have fmf fatty pipe and mix is 30-1. ,the spark arrester is fairly new and the packing is ok How much