RE: Welcome to Club SAITO !
I think I've determined how to accurately verify correct timing in my 125. I used an aluminum tube 8-9" long that fits snug inside tappet tube. Inserted solid pushrod into aluminum tube that fits snug into timing hole in cam. Removed play between pushrod and ID of aluminum tube with thin masking tape wrapped around pushrod to center pushrod in aluminum tube. Hold cam in place with homemade tool as cam is lowered and bolts threaded finger tight. Now rock crank back and forth and verify the slight play that is left is equal to both sides of 12:00. Should be accurate I think. Now, I'm sure I'm far from the first to do this, but I searched a fair bit online and couldn't find a better method. For what it's worth.