[BuzzLOL]

.. The cam/distributor rotate ONCE for each TWO revolutions of the crankshaft... this means the rotor can be pointed at #1 sparkplug terminal, but the crankshaft actually ONE full turn off while reading TDC on the pointer/damper...

.. When crank is proper, both valves on #1 cylinder will be closed, and the cylinder will hold air if pressurized with an air hose... (don't let the crank rotate from the pressure on the piston)... then rotate distributor till rotor pointing at #1...

.. Make sure gas in carb. (hold temp. tank above carb. till it's full)

.. Make sure spark at plugs as engine is rotated...

[bsa_bob]

I have the timing mark @tdc.verified by the sparking -plug. ?holding the thumb on the #1 cylinder? is this the same thing? bob s

[BuzzLOL]

.. Yes, thumb can be used if you feel definite pressure as #1 piston comes up...

[hcompton]

I am assuming it ran at one time so the cam chain is not off unless it jumped. Have you done a compression check? Just wondering if you got a hung valve.

I would replace all the tune up parts and try again. Wires, cap, rotor, points, coil and plugs. modual of its coverted to hei.

Replace it all and turn the key either it will fire or you got another issue that needs to be tracked down. But with ignition out of the why its easy to find out what is left compression check and verify the plugs are actually firing. Then most of the problems are out of the way. A shot of either can rule out the carb in a few seconds.