ORIGINAL: MAVROS
Hi Jon,
You are correct ...the TDC occurs when the mark on the crankshaft is on the bottom and the mark on the cam at the top.
The YS70 will not start otherwise.
REGARDS AND MANY THANKS TO ALL FOR YOUR HELP..
MAVROS
Guys....I'm not trying to rain/on/your/parade...but, TDC & the crank punch/mark at 6:00 are NOT one & the same! ....I have no idea what method you're using to determine TRUE TDC, but IF you are setting the cam punch/mark at 12:00 along with TRUE TDC, then you may or may not have hit on the correct tooth engagement....Will the engine run with the cam timing off one tooth?...ABSOLUTELY ...Will it run like "Yamada" intended? ....ABSOLUTELY NOT....