end of compression stroke and power stroke
Bad spark plug, bad spark plug wire
spark module is bad
The most common reason for a Honda 400EX not to fire is the need for a new spark plug. Try replacing the spark plug to see if that fixes the problem.
First of all, it the plug gap is too large the cyl. will not fire, or fire poorly. and, if there is no spark due to that, then the timing lite will not read anything.
Pull the wire off the spark plug, pull the spark plug out, plug the spark plug back into the wire, then have someone turn the engine over. You should see a blue spark jumping around the very bottom of the spark plug.
The spark plug is an electrical fire to ignite the compressed air/fuel mixture at the correct time.
Purchase a spark plug spark checker at your local auto parts store, unplug each plug and check for fire to the plug while turning over.
disconnected plug, bad plug, shorted plug, corrosion inside plug, missing plug
Start with a good tune up. Could be a bum spark plug or spark plug wire.
Spark plug may be bad or coil may have went bad.
Probably the coil for one of the cylinders, or the wire going from the coil to the spark plug if your coil isn't directly above the spark plug. Also a spark plug with cracked porcelin can cause what you are describing.
The fuel injector provides the fuel. The spark plug provides the fire.