Motorcycle Repair: ELECTRICAL WEAK-NO FIRE, stator plate, electrical diagnosis

Question
HI MARK,
I HAVE A 1986 CR 125. IT WAS RUNNING GREAT WHEN I PARKED IT ABOUT 4 MONTHS AGO. I HAVE STARTED IT A FEW TIMES IN BETWEEN BUT NEVER LEFT THE YARD. WENT TO START IT THE OTHER DAY AND NOTHING. IT HAS VERY WEAK FIRE ABOUT 2 TIMES EVERY 10 KICKS. ALL THE OTHER TIMES NOTHING. I CHANGED THE CDI CLEANED ALL THE WIRE CONNECTIONS FROM THE STATOR TO THE CDI.  SAME THING . I HAVE ALSO TRIED A COUPLE DIFFERENT PLUGS. MESSED AROUND WITH THE KILL SWITCH. NOTHING.  WHAT ELSE CAN GO BAD OR IS IT SOMEWHERE IN THE STATOR PLATE.
                                  THANKS
                            LEO_DUB@COMCAST.NET

Answer
Hi Leo,

The source of the problem may be difficult to locate. Electrical diagnosis should be performed.

Get a copy of the service manual to learn about testing system components and specs on test values.

Look for evidence of damaged wiring. Rodents love to chew insulation from wiring.

Check for loose or corroded electrical connectors. Check for evidence of water (damp) electrical connectors (water shorting from rain or washing).

Check ground connections for clean, tightly fastened connections.

Check the tether kill and/or engine stop switch for proper operation.

Check ignition pick-up coil, ignition coil windings, secondary lead, plug cap, and try a new or other spark plugs. Check plug gap.

Add dielectric grease to all electrical connectors to help prevent water shorting and corrosion formation.

Check fuel system for evidence of varnishing. Varnishing is less likey to occur with pre-mix fuel, however, fuel ingredients evaporates quickly. The resulting fuel recipe is slower to burn during the combustion porocess.

Respectfully,
Mark Shively