Motorcycle Repair: Starting a 1977 Yamaha Enduro DT 100 that has set still for 5 years, haynes manual, plug cap

Question
I resently aquired a 1977 Yamaha Enduro DT100 from a friend who left it to rot in a barn for the last 5 years or so (according to him, it was running 5 years ago). It is my first bike and so please bare with me. I've replaced the battery, checked the spark plug, checked the wiring and refilled the fluids. All seems OK. Everything is turned on that should be on. I hold down the clutch, put it in neutral and hit the kick start but the motor still refuses to start. What else can I check?   

Thanks, Lynne

Answer
Lynne,
  There are quite a few weak links that can cause this. Let's move backwards as they say. Remove the plug from the cylinder, put it back on the plug wire/cap and hold the threads to bare metal on the engine while holding JUST the plug cap and NOT the plug and crank over. You should see a STRONG BLUE spark.  If there is no spark, make sure the coil wire is in good condition including the plug cap. Make sure the coil has the correct low and high tension resistance. Check the condition of the wires from the stator (altenator) to the coil. Check the condition of the points and the settings (replace points if needed with a new condensor). Last of all check the kill switch to make sure it isn't broken. Other than that, the stator/magneto output could be to blame but this is the last thing to check. It requires an ossiliscope to make an accurate assesment. If you havent done so already, purchase the Haynes manual for that model, it will walk you through all the procedures I've mentioned. You may have to adjust, clean or replace the ignition points. They are located inside the magneto flywheel. You can adjust them through an elongated hole in the flywheel with a screwdriver and set of small feeler gauges.  If the points need to be replaced you must remove the flywheel and for this you will need a generic magneto flywheel puller which you can purchase at a bike shop for about $20. Bad points and/or their condenser are very frequently to blame, they are subject to regular malfuntioning and failure.  
 Other than these electrical delemas or if you HAVE spark you may dealing with a fuel delivery problem.  In that case you will need to clean and adjust the carburator and possibly install a small aftermarket inline fuel filter in the fuel line from the tank to the carb. to prevent rust from entering the carb.  Be sure there is fuel flow from the tank to the carb.

Hope this helps,
mike