timing on a Tecumseh 6.5 hp 4-cycle engine HELP!

How do you time engine? The mounting flange gasket was bad so I replaced it, while doing so the camshaft fell out i was unsure where the timing mark was. So I rolled the crankshaft timing mark to align with the dot and hobbing hole on the camshaft.I had my thumb over the spark plug hole while pulling on the starter rope. I could feel tdc. Put it all together,mounted engine on mower deck,screwed in spark plug,gas in tank,oil in crakcase,push primer bulb,holdhandle down, pulled rope.The rope pulled VERY hard I thought It was gonna rip my arm off! It will pull nice without the sparkplug in it. I have good spark too Nice and Blue I can arc about .05 inchs This has solid-state ignition.Timing is not correct! How do-or- what do i align the timingmarks?? pse help!