Timing Mark on Rincon
Think there is a removable plug on the right rear part of the engine, where you can view the T mark on the flywheel. I usually just take the spark plug out, and as slowly as possible turn the engine over with the recoil rope, watching the intake valve open and then fully close, then carefully put a long screwdriver through the spark plug hole til it contacts the top of the piston. continue to slowly turn the engine over until the piston is at the next TDC, using the screwdriver as a TDC gauge. If you go past, you will have to turn the engine over two times before compression stroke comes up again (or as before, just watch your intake valve). Get it as exactly as you can this way (err on the side of just past TDC) and it's plenty adequate to check valve lash.