Hi Phil; I am not sure about the 50 Saito as I do not have one. If it is like the 56 or the others that I have, there is a mark on the cam gear that lines up with the mark on the crank gear when the piston is at top dead center. Not sure if they are all that way, but there is an oil hole in the cam shaft that lines up with either the intake lifter guide, or the exhaust lifter guide, and you can make a tool to fit in there to hold the cam gear in position while installing it on the case. Maybe some one that has one will chime in here. Anyway, there are marks on the cam gear, and the crank, the one on the crank might be a little hard to find, but if you get the piston to TDC you shoud be able to find it.