I am not a mechanic. I am pretty good at working my way through things and own many different make motorcycles. I am trying to fire up 51' pan head after full rebuild. I did not do engine. It came to me "all done".... It is not starting. I am checking cam gear timing as I have spark/gas and have timed contact breaker(distributor) as should be. I notice the cam gears align every 2 rotations. What I have noticed is that in one rotation the front cylinder exhaust vale is just opening when gear marks are aligned. If I go around one rotation so pinion gear mark is straight up the valve opening is different. My ? is,,, does it matter on which rotation I align the gear marks????
Thanks for any input

 

AH yea

turn the engine to the line on the flywheel is in the center of the timing hole left side center top of the block with the plugs out and the rear cylinder intake push rod cover off the bike rear wheel up

two things come to play to confirm you firing the front cylinder - 1 the line for advance is in the center of the hole - 2 the rear intake valve is just opening

how to confirm you on the spot

a 1/4 inch hose and fitting it to the plug hole you will find when blowing in to the resistance is felt in the front and you can blow through on the rear if thats back wards your 180 out go around one more time