Motorcycle Repair: Weak Spark, honda cm200t, twinstar

Question
Hi Chris,

I have a 1981 Honda CM200T Twinstar that was given to me.  The bike is in great shape and it runs but it has a real weak spark on one cylinder, it runs but backfires real bad and has no power.  Can you give me some advice on what I should check first. I have replaced the spark plug but it did not help.  I have worked on some bikes before but they did not have CDI.  Could it be the condenser or would that effect both cylinders?
Thanks
Dave  

Answer
Hi Dave.
The Twinstar is a good little bike and it is also one of the early cdi box bikes.  It has ignition coils not condensors.  The coils are an odd lot.  You will want the repair manual because it has all of the specs for the bike.

 Check the coils against the specs in the book.  If they are outside of specs, then replace them.

 Check the ignition wiring from power to coils.  Use a multimeter for this as you are looking for shorts, which are not normally found visually.

Good luck.
FALCON