Motorcycle Repair: Timing a Bike 1981 Yamaha Virago 750, yamaha virago 750, rear cylinder head

Question
I had the fly Wheel off,to change the oil pump Chain i Retimed the rear Cylinder Head.which i had the head off to replace a Valve, Is it Required to retime the front Cylinder as well ? Bike wont Start all it does is bind up and Back Fire.Timing of the cylinders im not sure which marks to use for timeing the Cam.

Answer
Its probably a good idea to check the timing on the front cylinder.Some cam gears have only a dot to mark TDC there are sometimes lines or dots to run parallel along the top of the cylinder head with the extra mark on the top of the gear . Make sure the piston is in the TDC position and the cam lobes are positoned away from the rocker arms.So when you turn it over if it binds up the valves are hitting the piston and may bend them.This may have you doing the heads off and repairs again.