Ride_4_Fortune
You say that you ruled out the spark plug but, did you replace it with a new one?
Although it is rare, occasionally a spark plug will break down inside so it no longer will carry the voltage to the electrode tip.
If there is a layer of carbon on the central electrode, that can "short out" the plug so that although it is receiving enough electricity it will not produce a spark.
Although the carbon can be cleaned off it is easy to overlook the small amount that will short out the plug, therefore it is wise to replace the plug rather than to clean it.
While you've got the spark plug out be sure to test to see if it is sparking when the engine is kicked over. If it is not, you will know that the problem is electrical.
I'm sure you already know this but for those who don't, the first thing to check is the battery and the ignition switch.
This is easily done by turning the ignition switch on and then turning on the headlight and honking the horn. If the light fails to light and the horn fails to beep you've found the basic problem.
To check the spark plug and spark, remove the spark plug.
Re-attach the spark plug wire with the plug laying against the cylinder head in a position that allows you to see the electrodes.
Turn on the ignition.
Push the kick starter (or electrical starter button) to rotate the engine.
You should see a bright blue spark snapping across the spark plug gap.
If there is no spark and it is an old spark plug, replace it and test it again.
If there still is no spark check the "kill switch" on the right handlebar if your bike has one. (More than once, "helpful hands" have been known to "push the button" without your knowledge.)
Check all of the fuses.
Try turning the ignition switch on and off several times leaving it on while you test for spark again.
If still no spark, if your bike is not computer controlled, open or remove the cover for the ignition points. Push the kick starter to rotate the engine while watching for movement of the ignition points. They should be closed for most of the revolution and then open briefly when the cam lifts them. If they don't move you've found a problem.
They should open at least 0,4mm. (Check your owners manual for the proper gap.)
If they open and close properly, rotate the engine so the points stay open.
Turn on the ignition switch and while watching the electrode on the spark plug, bridge the open ends of the points with a screw driver or some other metal object to temporarily close them and to complete the electrical circuit). You only want to complete the electrical circuit with the screw driver so don't adjust anything.
That should produce a very small spark at the points.
If it does you will know that the wiring, fuses and ignition switch are working properly.
If no small spark is produced by bridging the point gap it indicates that either power is not reaching the points because of a bad fuse or wiring connection, faulty ignition switch or defective ignition coil. ( With some wiring systems the ignition switch has a separate set of contacts for the ignition coil so even though the headlight and horn worked it doesn't necessarily mean the ignition switch is good.
When you remove the screw driver or metal connector so that they are no longer completing the circuit it should produce a very good spark at the spark plug electrodes.
If you get the small sparks at the ignition points but no spark at the spark plug it indicates either the ignition coil is defective or the spark plug wire and its connector is the problem.
Spark plug wires have been known to go bad, especially the ones that use carbon to conduct the electricity.
Check to see that the spark plug wire is fully inserted into the ignition coil terminal. A Thumper like the RE can shake them loose.
The connector cap between the spark plug wire and the spark plug can also be a problem so make sure the cap is fully attached to the wire in a positive manner.
You can try replacing the spark plug wire and connector temporarily with an insulated wire to see if the coil is creating the high voltage but beware!
The output voltage from an ignition coil is over 15,000 volts which can knock you clear across the room if it gets to you. In a worst case situation it can be fatal.
Examining the wiring connections and fuses is fairly straight forward.
Unfortunately, testing the voltage at the coil requires the use of a volt-ohm meter and not everyone has one.
For those who do, with the ignition switch on and the ignition points
open you should be seeing 12 volts (or nearly 12 volts) on both of the coils low voltage terminals when checking the voltage to the engine case or some other ground.
For those who don't have a volt-ohm tester they should consider getting one. There are usually some very good ones available for a moderately low cost.
The other members pretty much covered the fuel issue and what to look for so I won't get into that area.
Good luck.
Jim